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http://www.bullfrogfilms.com/guides/biodguide.pdf

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Curved shapes have always sparked architects' fascination for evoking nature's beauty, fluidity, dynamism, and complexity. To replicate these shapes, however, is no easy task. From their two- or three-dimensional representation to their execution in their final materials, this represents an enormous difficulty, which requires technical expertise and a great amount of knowledge to achieve strong results. Thinking of new ways to produce organic shapes from natural materials is even more complicated.

In addition to this, working with a natural material such as wood carries its own set of peculiarities. Factors such as the species of wood, where the tree grew, what climate it faced, when it was cut, how it was sliced or dried, among many other variables, largely influence the final result. But it's hard for other materials to compare to the beauty and warmth that wooden surfaces bring to the built environment. If the appropriate processes are used, wood can be curved and remain in the desired shape - and for this, there is a number of known techniques which Australian company, Sculptform, has perfected.

Sculptform specializes in developing curved wooden Click-on Battens for walls and ceilings, enabling architects and builders to create buildable and affordable solutions for their curved concepts. When working with curved pieces of timber on a commercial scale, the factors that need to be considered depending on the intended application are wood species and density, the desired curve radius, and which easy and intuitive fastening method should be used for the construction.

Two methods are used to create the organic shapes:

Each timber Click-on batten, with the form foreseen for the project, is molded at their Australian factory with a groove in the back that serves as an interface between the support batten and the company's patented Click-on connection. Because of this, the assembly of complex parts is achieved quickly on site by simply clicking the batten into place.

An impressive case study is the design of Sculptform's Melbourne Design Studio, designed by Woods Bagot. It is a complex challenge to design a space for a brand - be it an office or concept store - and it is essential that the architect has a good understanding of the company, its demands, products, and aesthetics. Bruno Mendes, Principal at Woods Bagot, points out that "The ambition was to create a space to immerse in Sculptform's products and ethos, showcasing the company's hand-crafted philosophy. In form, the studio's architecture takes visitors on a physical journey through Sculptform's processes - showcasing the fully visible workshop space, the Co-lab, which sits at the heart of the design. Catering to groups of many different sizes, it is a space to host Melbourne's design community through integrated spatial features such as the auditorium seating and concealed screen.

"The intention was to create a sequence of events revealing the various interior spaces as people looped naturally through the space. The material of American White Oak is used on the floor, walls and ceiling - conjuring the experience of being enveloped by the distinctive timber. As a wayfinding element, the rising and ebbing tide of timber signifies the path through the showroom, looping back around to the communal space. The journey opens out to third spaces for focused work, natural light or collaborative meetings. These spaces are highlighted in contrasting materials and finishes. The physical loop hinges around the Co-lab, a workshop for the creative incubation of Sculptform's processes and where prototypes are created. A glazed wall makes the Co-lab's activities visible, bringing a theatricality into the showroom. Meeting rooms and breakout spaces lie behind timber-battened doors to maintain the continuity of the striking curved form. The workspaces incorporate agile methodologies with versatile meeting spaces, stand up meeting areas and an ideation table."

The project was a chance to collaborate on a close study of timber's possibilities with Sculptform, who also constructed the space and all the custom joinery. The design process explored timbers potential beyond its conventional form. This resulted in Sculptform importing equipment unavailable anywhere in Australia and developing new steam-bent timber production and application techniques to deliver the sweeping lines demanded by the ambitious concept.

The project even triggered more innovations and the creation of new products that would later be included in the company's product catalog. According to Bruno, "With their expertise in craft of product, and an enthusiasm to be pushed to new limits, Sculptform used steam-bending technologies and created a new pivot clip system which is now part of their product offering. The featured timber work showcases the Click-on Batten system, with the studio design leading to the development of new capabilities in steam-bent timber to create the curved feature bulkhead." In other words; technology, craftsmanship, and creativity walking hand-in-hand.

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Concave and Convex: Designing with Curved Wood

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Curved shapes have always sparked architects' fascination for evoking nature's beauty, fluidity, dynamism, and complexity. To replicate these shapes, however, is no easy task. From their two- or three-dimensional representation to their execution in their final materials, this represents an enormous difficulty, which requires technical expertise and a great amount of knowledge to achieve strong results.

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One way used to bend wood is by steaming it where you take a piece of wood and put it in an environment of high temperature and steam and moisture which permeates the wood and makes it flexible

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LVL (Laminated veneer lumber) is a strong way of manufacturing wood. LVL is made from thin sheets of timber, these sheets are bonded together and cut then have added moisture and heat to bond them. The strength of LVL relative to its weight is among the highest and higher than steel and lighter than concrete. Due to its manufacturing method, LVL is not limited by log size and it can be cheaper than most materials. Building with LVL is also quicker than building with most materials and has a less of a carbon footprint than most.

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Laminated veneer lumber (LVL) is one of the most widely used engineered wood products for constructional applications. It is a composite product manufactured from multiple thin layers of veneer that are aligned with the length of the finished lumber. This fact sheet summarizes basic manufacturing steps, advantages and disadvantages of LVL compared to other structural engineered wood-based products.

LVL production began in 1941. It was constructed into aircraft parts and was made from 3.6 mm thick Sitka spruce veneer. Because of great demand for LVL, the USDA Forest Products Laboratory did a substantial amount of research related to improving its strength properties. Douglas fir is the most commonly used raw material for LVL manufacture, in addition to Yellow poplar, Southern pine and other softwoods in the United States. Radiata pine and rubberwood are extensively used in New Zealand and Southeast Asian countries, respectively.

LVL Production

Veneer sheets with a thickness of 2.5 mm to 4.8 mm are produced using a rotary peeling technique. Typical veneer thickness for LVL production is 3.2 mm. Rotary peeling of the logs is carried out on a lathe, which incorporates geometry and positioning of a knife as main manufacturing parameters important role to the quality of the veneer. For example, the bevel angle of the knife selected is approximately 23 degrees for softwood to have efficient peeling.

The pressure bar applies a certain amount of pressure on the surface of veneer, so it will constantly be peeled from the log with a uniform thickness and without having any cracks. Figure 1 illustrates schematics of a typical rotary peeling veneer production with a fixed-nose bar and knife. The side of the veneer next to the knife-edge is called the loose side, while the other side is called the tight side. There are many fine cracks on the loose side of veneer due to lathe checks running parallel to the grain.

Figure 1. Rotary peeling veneer production.

A bolt, which is a short log depending on its diameters, may take 5 to 10 seconds to peel before its core is discharged and the charger is ready for the next cycle. Continuous ribbon-like veneer sheets are clipped to a certain width and dried to a target moisture content using jet tube dryers. Hot air is blown onto the surface of the veneer sheets and moisture is peeled off, reducing overall moisture content of veneer to a target point in the jet tube dryer. Usually 3 mm thick Douglas fir veneer may take 10-13 minutes to reduce its moisture content to 8 to 10 percent. Figure 2 shows a typical jet tube dryer.

Figure 2. Veneer jet tube dryer.

In general, LVL production is similar to that of structural plywood; however, the main difference between the two products is the grain orientation of each veneer. In the case of plywood, an odd number of veneer is assembled across each other, so the final product will not only have better mechanical properties, but also will be dimensionally more stable. In the case of LVL, more veneers are assembled along the longitudinal direction, so it will have similar properties to those of solid lumber, because each lamina is parallel to the board axis, as illustrated in Figure 3.

Figure 3. Structure of LVL.

Defects on each veneer are eliminated during the clipping process. Even if defects are left on each veneer sheet, random distribution of such defects during veneer assembly will make the final products more uniform and strength properties comparable to that of high-grade lumber. After exterior adhesive, usually phenol formaldehyde, is applied to the surface of each veneer sheet, they are assembled and pressed at temperatures ranging from 250 to 450 degrees Fahrenheit.

Compared to plywood press, LVL presses are longer. The press line could be either batch-type or continuous. A batch-type press may have one or several openings, which is more efficient for production of shorter length LVL. However, most mills use a continuous press line. Billets are manufactured up to 6-feet wide with a maximum shipping length of 80 feet. Figures 4 and 5 show a typical manufacturing process diagram of LVL.

Figure 4. Process diagram of LVL.

Figure 5. Manufacturing steps of LVL.

LVL Versatility

Laminated veneer lumber is a versatile wood-based product. Together with plywood, lumber or oriented strand board (OSB), LVL can be used for many structural applications. Some of the most popular uses of LVL include I-joists, header, rimboards, truck bed decking, roadway signpost, beam, truss, special applications such as skateboards, and custom-made panels for marine uses.

Advantages

Major advantages of LVL include its dimension, shape, high strength properties and low cost. The size of LVL is not limited by log size, due to its manufacturing method. LVL is one of the strongest wood-based construction materials relative to its density. Because it is manufactured with homogeneous quality that has a minimum number of defects or even distribution of defects, mechanical properties of the final product can be predicted. In general, LVL can be produced in different shapes depending on for what it will be used. It also has the great advantage of using wood resources efficiently.

Disadvantages

Conversely, LVL has several disadvantages as wood composites. Enhancement of strength properties of LVL by densification of veneer during the press is very limited. Although its dimensional stability is better than solid wood, the product may result in some defect, such as warping, if it is not properly stored in the warehouse. Also, LVL requires high capital investment to have relatively low production cost. Therefore, high demand is necessary to have a profitable operation.

Further Information

Detailed information about LVL manufacturing and its properties also can be found in the following literature:

Smulski, S. (Ed.) (1997). Engineered Wood Products. PFS Research Foundation: Madison, Wisconsin.

Bowyer, J., Smulsky, R., & Haygreen, J. (2007). Forest Products and Wood Science. Blackwell Publishing: Boston, Massachusetts.

Baldwin,R. (1995). Plywood and Veneer-Based Products, Manufacturing Practices. Miller Freeman: San Francisco, California.

American Plywood Association. The Engineered Wood Association. Retrieved from www.apa.wood.org

Salim Hiziroglu
FAPC Wood Products Specialist

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Laminated Veneer Lumber (LVL) as a Construction Material - Oklahoma State University

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Laminated veneer lumber (LVL) is one of the most widely used engineered wood products for constructional applications. It is a composite product manufactured from multiple thin layers of veneer that are aligned with the length of the finished lumber. This fact sheet summarizes basic manufacturing steps, advantages and disadvantages of LVL compared to other structural engineered wood-based products.

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Wood is a Natural material that processes as low carbon foot print , compared with supplementary building material. The psychological attraction of wood is its low cost which made it a popular building material in residential construction

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https://www.woodmagazine.com/materials-guide/lumber/what-makes-wood-beautiful

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What makes wood beautiful?

If you've been working with wood for very long, you realize that each species has different characteristics and appeal. You probably know, too, that even a pair of boards taken from two logs of the same species may not look exactly alike. That's because color, luster, texture, grain, and figure all come into play for a species' visual appeal. And it's one or more of these characteristics that put a high value on the most favored hardwoods used for decorative purposes. Now you'll learn just what they are.

In hardwoods, color occurs naturally across a wide range. There are purples, yellows, oranges, almond tones, browns, cinnamons, and shades of red. And color plays a major role in determining the final use of the wood. East Indian rosewood's decorative color makes an attractive turned bowl. But a nearly colorless wood, such as birch, makes a good mixing spoon.

Wood has color due to infiltrates that interact with the cellulose of its cell walls and the lignin that bonds them together. These infiltrates are soluble materials (sometimes called extractives) that a tree draws from the soil where it grows. Various species react to the infiltrates in different ways, thus creating contrasts among them. But that's also why even within a species the wood's color can vary. Walnut harvested from the cool limestone bluffs of northeast Iowa, for instance, will differ in color from that grown in central Kansas.

Freshly sawn green wood from a tree also can change color when exposed to air and light, sometimes drastically. South American purpleheart turns from light brown to purple. Osage-orange is a bright yellow-orange when first cut or planed, but shortly turns brown. Some woods, such as teak, fade under strong light but darken by moderate light. The moist heat of kiln drying will change a wood's color, too. As an example, the lighter color of walnut's sapwood evens out in a kiln to match the darker heartwood.

Luster in the light

A wood that has luster reflects light from its cell walls and appears to have a natural sheen. But any infiltrates in a wood's cell walls that give it color reduce its luster. Because of this, light-colored hardwoods will have luster, as does the light sapwood of darker hardwoods. Lack of luster, however, does not mean that a wood won't take a high polish when finely sanded, then buffed. Finishing also adds luster.

In general, quartersawn wood has more luster than flatsawn, as with white oak. The ray flecks in white oak exposed by this manner of cutting reflect light. Too, woods with lots of figure, such as curly and fiddleback maple, display added luster due to the cell walls' changing angle to the light.

Texture to feel

When wood is said to be "coarse" grained or "fine" grained, it's a reference to its texture. And a wood's texture depends on the relative size and variation of size in its cells and the width and abundance of its rays. You actually can feel the difference between fine-textured wood with small cells and thin rays and coarse-textured wood with wide vessels and broad rays. Red oak, for example, rates as coarse-textured, while hard maple is fine-textured. Walnut, however, is moderately coarse-textured, while holly is very fine-textured.

Texture is only sensory. A wood's texture has little to do with how it saws or machines.

Grain follows

Grain is a term that's often misused. It does not refer to the natural pattern seen on the surface of wood. That's figure. Technically, grain means the orientation of the wood cells. Under that definition, there are six general types of grain.

Straight grain indicates that the cells and fibrous components run completely or nearly parallel to the vertical plane of the tree trunk and the log that came from it.

Irregular wood grain implies irregular variations from the parallel orientation of the grain to the log. This most often happens around knots.

Diagonal grain describes what results when an otherwise straight-grained log is not sawn parallel to its vertical axis -- in other words, angled sawing.

Spiral grain happens when the cells and fibers grow in a left or right twisted configuration around the trunk of a tree.

Interlocked grain occurs when each successive layer of new growth on a tree runs in a different direction.

Wavy grain is produced when the direction of the fibers alternate so that a board's surface looks like a washboard, as with the figure pattern of curly maple.

Figure in the patterns

Although some grain configurations in wood frequently do result in figure, the word describes the pattern that often occurs when several features interact, including irregular grain, rays, color deposits, and growth rings. Irregular grain in crotches and burls causes "feather" figure, "plum-pudding" figure, and others. Interlocked grain promotes "ribbon" figure and "Bird's-eye." Wavy grain creates "fiddleback" or "tigerstripe" figure.

Highly sought and expensive figured veneers are regularly manufactured by slicing or peeling a log with irregular or interlocked grain in a special manner. Changing the angle of cut enhances the irregularities and yields special effects. It' the same with lumber; quartersawing a regular-grained wood sometimes results in figure pattern, again as with white oak and its ray flecks.

Another term used by woodworkers to describe what loosely could be called figure pattern is "character marks." This refers to naturally occurring ingrown knots, "tracks" left by insects in the living tree, "bird peck," and other signs that make the wood appear less than perfect. However, a skilled craftsman employing wood with character marks in a project can literally turn a sow's ear into a silk purse.

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If you've been working with wood for very long, you realize that each species has different characteristics and appeal. You probably know, too, that even a pair of boards taken from two logs of the same species may not look exactly alike.

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Wood has been used as a building material for millennia, but the biophilic benefits of wood are only recently being studied and understood. While many people agree wood is visually pleasing, researchers are discovering that wood can contribute to the health and well-being of building occupants.

"Wood gives mother nature fingerprints in our buildings.”

A recent study showed that people in workplaces with less than 20% natural wood surfaces were up to 30% less satisfied with both their working life and physical workplace compared to those with a high proportion of wood.

"According to the study, the practical implication of this effect is that wood may be able to be applied indoors to provide stress reduction as a part of the evidence-based and biophilic design."

https://www.thinkwood.com/benefits-of-using-wood/wood-and-well-being

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wood provides an acceptable cost benefit in 2021. with an average expense of 7-16 usd per sqft, with an average life span of 100+ years

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Wood is a durable building material that can be used in almost any building application

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Wood is a durable building material that can be used in almost any building application

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https://www.thinkwood.com/education/role-of-wood-products-in-green-building

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Architects can incorporate sustainable features into their designs through their choice of building materials. Material choice greatly affects the environmental impact of buildings, both during construction and over the building's lifecycle. Wood is a renewable, durable building material that can be used in almost any building application. Wood products typically require less energy to produce than other building materials. Green building standards also recognize wood's contribution to improved energy performance over time. Learn about tools and certifications for green building in this CEU.

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The Role of Wood Products in Green Building - Think Wood

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Architects can incorporate sustainable features into their designs through their choice of building materials. Material choice greatly affects the environmental impact of buildings, both during construction and over the building's lifecycle. Wood is a renewable, durable building material that can be used in almost any building application.

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A chemical bath and a hot-press can transform wood into a material that is stronger than steel and the process, and others like it, could make the humble material an eco-friendly alternative to using plastics and metals in the manufacture of cars and buildings

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Wood helps keep carbon out of the atmosphere which helps to mitigate climate change because trees store carbon dioxide as they grow and after harvest, wood products continue to store much of this carbon

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Different Biomes have different types of trees

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Different Biomes have different types of trees

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http://web.fscj.edu/David.Byres/botanynotes/botanych26notes.html

http://lifeofplant.blogspot.com/2011/12/types-of-biomes.html

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On the Use and Meaning of Wood in Chinese Imperial Architecture

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On the Use and Meaning of Wood in Chinese Imperial Architecture

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Wood is the primary structural building material of Chinese imperial architecture. This thesis argues that there are practical and symbolic reasons why wood was chosen instead of stone for politically and ritually important structures. Stone is connected to immortality and death so for buildings that must endure through time, masonry was the preferred building material for funerary contexts. Wood represents life and regrowth and was thus the preferred material for living structures. However, wood is vulnerable and such buildings degraded over time, so they had to be habitually rebuilt. This thesis then seeks to explore the ways in which this practice of rebuilding works within modern theories of architectural authenticity and modern conservation methods. It will argue that Imperial Chinese architecture does work within certain types of architectural authenticity and conservation methods.

https://scholarsbank.uoregon.edu/xmlui/handle/1794/19659

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On the Use and Meaning of Wood in Chinese Imperial Architecture

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Wood is the primary structural building material of Chinese imperial architecture. This thesis argues that there are practical and symbolic reasons why wood was chosen instead of stone for politically and ritually important structures. Stone is connected to immortality and death so for buildings that must endure through time, masonry was the preferred building material for funerary contexts.

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Strong. It is no accident that wood has been used in construction for thousands of years. It is an incredibly durable material and can provide a strong structure for buildings. Wood can actually be better at supporting its own weight than other materials such as steel.

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A tree is defined as a woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground. Bamboo doesn't fit under this definition though because its a grass apparently.

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When we think of wood as a building material, we often think about how prone it is to burning. While wood does burn easier than materials like concrete or steel, Timber offers a solution to the problem. Fires char the outer layer of the wood, allowing the insulated inside to remain safe and integral. This is a game changer as it passed tests from fire control departments in buildings with flying colors. Having lasted a whole hour more than required, timber proved not only to be a good structural material but a resistant one as well.

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Since immemorial time, humans have constructed their shelter and homes using wood. Gradually these structures grew more complex, but wood has continued to play a fundamental role in architecture and construction. Today, especially due to growing concerns about climate change and carbon emissions, wood has been regaining significance as an important building material for the future, if used consciously and sustainably. Wood's structural performance capabilities make it appropriate for a broad range of applications-from the light-duty repetitive framing common in low and mid-rise structures to the larger and heavier, often hybrid systems, used to build arenas, offices, universities and other buildings where long spans and tall walls are required.

Mass timber is a category of framing often using large panelized solid wood construction including cross-laminated timber (CLT), nail laminated timber (NLT), dowel-laminated timber (DLT), and glued laminated timber (glulam) panels for floor and wall framing. It offers exceptional stability and strength and have made wood a viable alternative to steel and concrete for many applications, including taller structures. As timber construction continues to rise, it is important to understand wood's proven performance when it comes to fire protection. Fire is a danger for all buildings and construction sites - regardless of building material. Fires start in the contents and furnishings we bring into our homes and offices, and occur in concrete, steel, masonry, and wood buildings alike, and all building materials experience negative impacts from prolonged exposure to flames. Steel buckles, concrete spalls, wood burns. What's most important is building to code to ensure safe buildings for occupants and first responders.

Mass timber enables inherent fire resistance through the insulation of inner layers. When wood is exposed to fire, the exposed surface burns, creating a natural protective charred layer. Char acts as insulation, delaying the onset of heating of the core of wood below. Due to the solid block makeup of mass timber, air and fire are inhibited in their travel. Char forms at a predictable rate (1.5in/hr), which slows combustion, and the spread of fire.

Robust mass timber fire testing in recent years demonstrates the safety of this sustainable, renewable building material. Precisely, because of the structural and fire-resistant characteristics of CLT walls, floors, and solid wood structures, in 2016, the International Code Council established a committee of industry experts to examine and propose appropriate standards for this building system. Developments on this subject can be followed at this link. To assess fire behavior in these building systems, a series of rigorously monitored fire tests were developed that provided valuable data for the alteration of fire codes and regulations for tall wooden buildings. Each of the five simulated materials and situations are designed to replicate real-world conditions in five identical environment scenarios. A three-minute video capturing the highlights of each test is included in this playlist.

Research and analysis show that mass timber not only meets prescribed fire safety and safety codes, but can exceed them. In a fire test, a 7 inch thick (about 18 cm) wall of plaster coated Cross Laminated Wood (CLT) lasted 3 hours and 6 minutes. This result is an hour longer than current fire code requirements.

Fire Safety in Occupied Buildings

Fire departments are called to control fires in non-sprinklered buildings almost three times more often than buildings with adequate fire protection measures in place. Fires in sprinkler-protected buildings were smaller and contained to a single room over 96% of the time. Other important fire safety protection measures include:

Consulting with Fire Departments

Constructing Firewalls

Using Gypsum Encapsulation

Installing Automatic Sprinkler Systems

Implementing Fire Detection Systems

Developing Comprehensive Evacuation Plans

The increased use of exposed mass timber in multi-family and commercial buildings has created a need for greater understanding of the fire design procedures of these types of structures. Under the 2018 IBC, many mass timber products are permitted and multiple design routes exist for demonstrating compliance with fire-related provisions of the building code. Mass timber elements can be designed so a sufficient cross-section of wood remains to sustain the design loads for the required duration of fire exposure. This sets mass timber apart as a unique building material-one that is able to achieve structural performance and passive fire-resistance objectives for larger and taller wood buildings than ever before, while offering enhanced aesthetic value and environmental benefits.
For further information, download Think Wood's Fire Performance eBook and review WoodWorks' Fire Design of Mass Timber Members.

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Timber Takes the Heat: What Every Architect Should Know About Wood Construction and Fire Protection

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Since immemorial time, humans have constructed their shelter and homes using wood. Gradually these structures grew more complex, but wood has continued to play a fundamental role in architecture and construction. Today, especially due to growing concerns about climate change and carbon emissions, wood has been regaining significance as an important building material for the future, if used consciously and sustainably.

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Wood is a suitable material to improve sustainability because even with deforestation, wooden buildings are vastly preferable to those built of concrete, brick, aluminum, and steel.

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Wood grain is the longitudinal arrangement of wood fibers or the pattern resulting from such an arrangement.

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Some wood can naturally resist water more than others

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Some wood can naturally resist water more than others

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Wood can become waterproof with special treatments. ... Wood is porous, so it absorbs water and, when it does, the wood expands and warps causing structural problems. While no wood is completely waterproof, a few species of wood resist water better than others, and some paints and sealers make wood waterproof.

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Rings happen because of the change in growth speed through winter, spring, summer and fall, so one ring usually marks the passage of one year in the life of the tree

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Colour covers a wide range—yellow, green, red, brown, black, and nearly pure white woods exist, but most woods are shades of white and brown. Variations may show on a single piece of wood, depending on colour differences between heartwood, sapwood, earlywood, latewood, rays, and resin canals.

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https://blog.pachamama.org/people-and-trees-intimately-connected-through-the-ages

In the current journal Environmental Pollution, forester Dave Nowak and colleagues found that trees prevented 850 human deaths and 670,000 cases of acute respiratory symptoms in 2010 alone. That was related to 17 tonnes of air pollution removed by trees and forests, which physically intercept particulate matter and absorb gasses through their leaves.

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Featured Image: Tree of Life by Judith Shaw

Trees Speak to the Soul of Human Beings

It is no wonder that trees have captured the human imagination since the beginning of time. Their strength, deeply rooted in the Earth, is an inspiration. Their trunk and branches are a wonder of nature because they stand sturdy and impenetrable most of the time, yet they can flex and sway with the wind when needed.

The whisper of a breeze in their leaves or the sight of ants marching in a straight line up or down their trunks remind us of the magic of nature that trees embody. They live for hundreds or even thousands of years, and so we revere them as keepers of past secrets and sentinels of the future.

Watching their cycles of growth, shedding of leaves, and re-flowering in the spring, people have long perceived trees as powerful symbols of life, death, and renewal. Since the beginning of time, humans have had a sense that trees are sentient beings just like us, that they can feel pain, that they bleed when they are hurt. Trees even look like us. People have a trunk; trees have arms. And so we innately feel a deep connection to them.

Many people say they can feel a tree's vibrational energy when placing their hand upon its bark. With their deep roots, trees carry significant grounding energy. We naturally feel peace and serenity when walking in the shade of trees or on a forest trail.

Trees Help Us Every Day

A recent study shows that trees remove so much pollution from the air that they "prevented 850 human deaths and 670,000 cases of acute respiratory symptoms in 2010 alone." When an insect called the emerald ash borer killed off a significant number of trees in the American Midwest in the 1990's and 2000's, rates of human death from cardiovascular and respiratory illness increased.

More difficult to quantify is the psychological effect that trees have on people. People who spend time outdoors, or even those who have access to windows looking out at trees, have been shown to have better health than those who do not.

The Universal Tree of Life: Both Ancient and Modern

The concept of a Tree of Life, often symbolizing the connections between all life forms, is found in many religions and philosophies, dating back as early as ancient Egypt. The Egyptian tree of life symbolized creation and represented the chain of events that brought everything into existence.

Fast forward to modern science. The tree has become the quintessential symbol of biological evolution, as its ever-branching image poignantly depicts the unmistakable interconnections between all living species on the Earth.

The beautiful Tree of Life painting at the top of the article was shared with us by artist Judith Shaw. It was inspired by the ancient symbol of the Tree of Life as well as by Sacred Geometry.

The Tree Leaf and Eternal Life

Consider this beautiful commentary from Thich Nhat Hanh reflecting on a tree leaf:

"I asked the leaf whether it was frightened because it was autumn and the other leaves were falling. The leaf told me, "No. During the whole spring and summer I was completely alive. I worked hard to help nourish the tree, and now much of me is in the tree. I am not limited by this form. I am also the whole tree, and when I go back to the soil, I will continue to nourish the tree. So I don't worry at all. As I leave this branch and float to the ground, I will wave to the tree and tell her, 'I will see you again very soon.'

... That day there was a wind blowing and, after a while, I saw the leaf leave the branch and float down to the soil, dancing joyfully, because as it floated it saw itself already there in the tree. It was so happy. I bowed my head, knowing that I have a lot to learn from the leaf because it is not afraid-it knew nothing can be born and nothing can die."

Cultural Beliefs About Trees

Trees are considered sacred in virtually every place where humans have settled, a sign of the deep relationship betwen people and trees.

There are many profound beliefs surrounding trees that people have held for millennia. Here are some interesting and touching examples:

For the Sng'oi people of Malaysia, a person and a tree can belong with each other, and this relationship is maintained for life. Certain trees and certain people belong together. When a person belongs with a tree, they also belong with its offspring: any trees that grow from the seeds of the first tree, no matter how far the seeds may scatter. The Sng'oi people call upon their intuition to know which child trees have sprung from which parent trees.

The World Tree is said to dwell in three worlds: Its roots reach down to the underworld, its trunk sits on the Earth, and its branches extend up to the heavens. Many cultures share a belief that this tree is the Axis Mundi or World Axis which supports or holds up the cosmos. For the Mayan peoples, the Axis Mundi was a massive Ceiba (in other cultures, it is called Kapok) tree that stands at the center of the world. The Mayan beliefs reflect that human souls first came into being as the sacred white flowers on the branches of the Ceiba tree. Souls of the dead Mayan ancestors rose from the roots of the Axis Mundi up through its branches and into the celestial realms.

In Germanic regions, it was believed that mankind was created from tree trunks, echoing the perception that people and trees have much in common.

In Sweden, some trees were considered "wardens" and could guard a home from bad luck. The warden was usually a very old tree growing on the lot near the home. The family living there had such great respect for the tree that they would often adopt a surname related to the name of the tree.

A well-known sacred tree in Norse mythology was Yggdrasil, a giant ash tree that was said to link and shelter the nine worlds that were believed to exist.

In Irish and English folklore, fairies would be found wherever Ash, Oak, and Hawthorne trees grew together. Hawthorn trees were regarded as a powerful symbol of protection, and were often planted near houses to ward off lightning as well as evil spirits. On the dawn of Beltane, it was believed that women who bathed in the dew from a Hawthorne blossom would become beautiful, and men who washed their hands in the dew would become skilled craftsmen.

Buddhists have a deep reverence for the Bodhi tree, a type of fig tree with heart-shaped leaves, beneath which the Buddha is said to have meditated for 49 days, trying to reconcile his mind to the fact that there was suffering in the world. On the 49th day, he stood and thanked the tree for providing shade for him, and in that instant he attained enlightenment. Today, in the same location where the Buddha is believed to have sat, there grows a descendant of that same Bodhi tree. Buddhist myths say that the tree will live there until the world is destroyed, and the place where it grows will be the last place to be destroyed; and when the world is reborn, that site will be the first place to appear.

The villagers of Piplantri, in Rajasthan, India, celebrate the birth of each little girl by planting 111 trees in her honor. The entire village works together to plant and care for the trees. This tradition not only ensures that the environment will be able to support the increasing population of the village, but it has also brought harmony and a drop in crime to the village.

In Malaysia, people maintain a very intimate relationship with trees. "There is a practice of tree planting around houses to the extent that the walls and wooden structures are allowed to give way to the roots of creeping plants, purposely sown at the bases of these structures." The graveyards in Malaysia are covered so thickly with trees that the entire grounds are cool and sheltered from the tropical sun. The trees are allowed to take root into the graves and it is said that the trees whisper prayers to the creator asking for forgiveness of past transgressions of those buried in that place.

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People and Trees: Intimately Connected Through the Ages

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Featured Image: Tree of Life by Judith Shaw It is no wonder that trees have captured the human imagination since the beginning of time. Their strength, deeply rooted in the Earth, is an inspiration. Their trunk and branches are a wonder of nature because they stand sturdy and impenetrable most of the time, yet they can flex and sway with the wind when needed.

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Wood prevents echoes from bouncing around the room by absorbing sound waves.

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Balsa wood is used in models because it is lightweight, has minimal grain, and its soft which makes it the easiest wood to carve and shape

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https://homereference.net/steel-vs-wood-framing/

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© Lev / Fotolia

Once used primarily for industrial and commercial buildings, steel framing has become increasingly popular among homeowners. Both wood and steel are effective, renewable building materials, and the final choice may come down to which type of frame suits your project more. Before deciding, it's important to know how steel frames stack up against wood.

Advantages of Steel

Steel is most commonly used in larger facilities due to its ability to support weight over wide areas. However, steel has a few advantages over wood when it comes to smaller buildings as well.

Higher Resistance

Steel has a much higher resistance to degradation than wood. For example, a leaky roof will not lead to rotting. Floors held up by a steel infrastructure will also never warp, keeping the surface level. Termites and other pests cannot burrow into the steel beams making infestations less likely and cheaper to treat. Finally, steel is non-combustible; meaning the frame of your home will remain intact even after a major fire.

Stronger

As a building material, steel is able to withstand natural disasters such as earthquakes or hurricanes. This means that insurance for steel-framed homes are often lower, especially in disaster-prone regions. When used for a properly maintained home, steel frames have the potential to last for several generations. Additionally, it is able to support more weight for longer periods, such as concrete floors or metal tile roofs.

Disadvantages Against Wood Frames

© JRB / Fotolia

No building material is perfect, and steel is no exception. The following are a few issues which may make a metal frame less ideal for your personal project.

Design Limitations

Steel framed homes are sturdy, but have far less flexibility when it comes to roof design. Unlike wood post roofs, metal framed roofs rarely have high pitch, dormers, or overhangs. While it may be possible to add a wooden frame for the roof of a steel-framed home, it is neither efficient nor as structurally sound as using a single frame type and as such may be a violation of local building codes.

Insulation

Metal is a natural conductor, and thus more difficult to insulate. This is especially true in colder months or climates, where the entire frame will drop in temperature if not adequately insulated. This may lead to higher energy costs, increasing both your bills and carbon footprint.

Rust

While steel is immune to rot, rust can become a very real problem. This is especially true when the metal is exposed to standing water or a major leak for long periods of time. If left untreated, rust will affect the stability of your infrastructure and lead to costly repairs.

Comparing Costs

Before choosing whether wood or steel for your home's frame, one of the most important and complex factors to examine is the cost. There are both short term and long term variables to consider. In the event you are planning to purchase an existing home, the short-term costs may not apply, and vice-versa if you are building or renovating a home with the intent to sell.

Short Term Costs

Construction costs are significantly higher for a metal frame. In addition to needing special tools, metal frames will cost between 10 and 20 percent more than wood frames. Keep in mind that you will require extra supplies such as fasteners and electrical boxes to complete the frame. Contractors may also include additional charges for steel construction depending upon how rare steel framed buildings are in your area.

Long Term Costs

Maintaining your home usually does not bring up images of infrastructure maintenance, but there are certain factors which may lead to additional costs or savings as time passes. Some of these include:

Wood frame: warping, rot, mold, termite damage, stud damage, natural disaster damage such as flooding or earthquakes; easy to add extensions or add/remove walls.

Steel frame: heating/cooling and insulation costs, rust, additional work when adding an extension or modifying walls; generally lower insurance fees in some areas.

Additional References

The Department of Housing and Urban Development offers an online PDF report detailing a long-term thermal performance comparison between wood and steel framed homes.

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Once used primarily for industrial and commercial buildings, steel framing has become increasingly popular among homeowners. Both wood and steel are effective, renewable building materials, and the final choice may come down to which type of frame suits your project more. Before deciding, it's important to know how steel frames stack up against wood.

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It takes years for it to decay. 50-100 years to decay as a whole. But it will rot faster if in a wet climate vs dry climate.

Signs of wet rot include:

Isolated fungus on wood

Damaged, peeling, and/or flaking paint

Wood that has a soft, spongy texture

Wood that has a darkened appearance

Dry rot signs include:

The appearance of white/yellow/brown patches (fruiting bodies) on wood

Brittle, damaged wood

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Woods are ideal for insulation, some for acoustics, grain, color, appearance, and others for structural frames, walls, floors, ceilings and furniture.

Wood can be painted in any color and can be waxed and varnished which’ll brandish its natural finesse. It can be carved, cut, glued and nailed.

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Wood is used to design and this movement has started up recently. Nature is something we seem so it is only natural we are drawn to wood inside buildings as a design element. Wood and plants are used to bring nature into the spaces we otherwise would not be in touch with. It can also be curved in walls or ceilings to create the flow of movement in a space as well as help with keeping a space clean and healthy.

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Reclaimed Wood Biophilic Design Elements | Centennial Woods

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Build a connection to nature inside your living and work spaces with reclaimed wood from Centennial Woods. Discover how reclaimed wood can act as a biophilic design element.

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Relating to us:

physical

spiritual

artistic

ceremonial

sense of place

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Through the ages and in all corners of the globe, people have looked to trees to make sense of our lives, honoring their transcendental qualities in a variety of ways. How has our interconnectedness with trees manifested itself? The answers are many, but these pages present just a few examples - culled from my own experience and that of others, including the research of Dr. Nalini Nadkarni, discussed in her book "Between Earth and Sky: Our Intimate Connections to Trees" - of how trees meet our needs at every level of human experience.
TREES AND OUR PHYSICAL SELVES
Our strong connections with trees may be based, in part, on the fact that trees and humans share similar physical characteristics. We stand upright, have a crown on top and mobile limbs stemming from a central trunk. The pattern of the tubular branches (bronchi) in our lungs is similar to the root system of many trees.

At the physical level, trees provide oxygen, food and other material necessities, such as paper and building materials.

Trees also provide physical security in the form of shelter, windbreaks and a sense of place - of rootedness. Humans have a strong preference for landscapes with trees or wooded areas. In the real estate market, we find that trees increase the property value of homes by four to 15 percent. In areas where 30 percent or more of the land is federally protected, employment growth over the last 40 years has been three times higher than average, and commercial areas with trees tend to attract more customers, who shop longer and spend up to 12 percent more.

Trees play a role in the context of play and recreation, as well. We use trees for crafting musical instruments and constructing boats and canoes. We have picnics under the trees and take walks through the woods. Eight of the 25 most popular tourist destinations in the United States are on National Park Service land.

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People and Trees: An Intimate Connection - American Forests

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Through the ages and in all corners of the globe, people have looked to trees to make sense of our lives, honoring their transcendental qualities in a variety of ways. How has our interconnectedness with trees manifested itself?

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Growth rings are visible because of macroscopic differences in structure between earlywood and latewood

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What can we do to ensure wood structures last?

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The bark part of the wood that surrounds the cylinder trunk of the tree is a insulating function.

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Parts of the trunk and how rings interact with different climates

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Parts of the trunk and how rings interact with different climates

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transverse section (cross section) of a tree trunk shows three parts—pith, wood, and bark. Between the wood and bark is the cambium, although this thin layer of tissue is indistinguishable with the naked eye or a hand lens. Pith is normally small and located at the centre of the transverse section. Wood is marked by the presence of concentric layers known as growth rings or annual rings. In temperate regions one growth ring is normally produced during each season of growth, but false rings may also be present, and in some cases certain rings may be locally discontinuous. In tropical regions growth rings are formed in response to wet and dry periods or other, incompletely understood factors. For these reasons the term growth ring is preferred over annual ring. Barring the above deviations, however, the number of growth rings, as counted in a transverse section near the ground, can be used to find the age of a tree.

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Wood is hygroscopic, which means just like a sponge the moisture content will change depending on the relative humidity of the surrounding air. When humidity increases, the wood absorbs moisture from the air causing the wood to expand

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https://www.wagnermeters.com/moisture-meters/wood-info/advantages-wood-building/

Tensile strength: light weight but strong support

Electrical and Heat resistance: stability to building and safety implications during certain fire situations

Sound absorption: minimize echo

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Wood is obviously both a common and a historical choice as a building material. However, in the past few decades, there has been a move away from wood in favor of engineered products or metals like aluminum.

While the desire to not rely on the world's forests for building demands is well-intentioned, the advantages of wood as a building material still outweigh other products on the market when looking at the environmental impact and performance.

Wood's Characteristics

Why Is Wood a Good Building Material?

Tensile strength - For being a relatively lightweight building material, wood outperforms even steel when it comes to breaking length (or self-support length). Simply put, it can support its own weight better, which allows for larger spaces and fewer necessary supports in some building designs.

Electrical and heat resistance - Wood has a natural resistance to electrical conduction when dried to standard moisture content (MC) levels, usually between 7%-12% for most wood species. (This conductivity is, in fact, the basis for one type of moisture measurement system.) Its strength and dimensions are also not significantly affected by heat, providing stability to the finished building and even safety implications for certain fire situations.

Sound absorption - Wood's acoustic properties make it ideal for minimizing echo in living or office spaces. Wood absorbs sound, rather than reflecting or amplifying it, and can help significantly reduce noise levels for additional comfort.

Beauty - With the wide variety of species available, wood presents an incredible range of aesthetic options, as well as provides varied mechanical, acoustic, thermal properties along with others that can be selected based on the need of the building project.

Wood's Green Advantage

At a time when ecological concerns are high, the trend has been to move away from wood as a building material in order to prevent deforestation, in part as an attempt to manage greenhouse gasses.

However, a closer look at the reasons for this thinking can prove to be slightly off track. Wood has several advantages that help both the builder and the environment.

Wood Is Renewable

Unlike concrete or metals, wood is a building material that can be grown and regrown through natural processes and also through replanting and forestry management programs. Select harvesting and other practices allow growth to continue while larger trees are harvested.

While the forests are growing (via solar energy), they are also naturally and efficiently removing carbon dioxide from the environment. It's a bonus unique to wood.

Shop Orion Moisture Meters

Wood Is More Readily Processed for Use

When compared to building materials like steel or concrete, the life cycle of wood has a lower overall impact on the environment than its counterparts and as a result, also costs significantly less to produce. Wastewater production and environmental impact are also significantly lower in wood manufacturing processes, particularly when compared to steel.

Many lumber mills use wood byproducts (chips, bark, etc.) as biofuel for their facilities to reduce the fossil fuel burden of the production process, and moisture measurement systems like Wagner Meters' Moisture Management and Grade Recovery Program allow mills to maximize efficiency and produce less sub-grade and waste materials in the drying process.

As forest management and replanting programs continue to grow, these benefits are continually multiplied.

Wood Emits Lower Volatile Organic Compounds

As a natural building material, wood emits significantly lower volatile organic compounds (VOCs) and carbon dioxide off-gasses than aluminum, steel, concrete and plastics. This is not, however, necessarily true of engineered wood products or composite wood products.

Wood's lower VOC impact is of particular benefit to homes and offices that are occupied on a daily basis. In fact, one of the things wood does give off is a natural organic compound that relaxes people-it's not just the warmth of wood's color that creates such an inviting effect.

Wood Enhances Energy Efficiency

Wood has a higher insulation rating than either steel or plastic as a result of its natural cellular structure. This means that homes and buildings require less energy to maintain heating and cooling, plus wood can help regulate humidity levels to a small degree. (See below on Optimizing Wood's Use with MC Measurement.) One source suggests that a hardwood floor installed over a wood subfloor provides the same insulation value as a 22-inch concrete floor. (1)

Wood Is Biodegradable

One of the biggest challenges of many building materials, including concrete, metal, and plastics, is that when they are discarded, they take an impossibly long time to decompose. When exposed to natural climate conditions, wood will break down much more quickly and actually replenish the soil in the process.

On the flip side, understanding the role of moisture and wood rot means that when conditions for the wood are optimized, the lifespan of the building or floor can easily outlive the lifespan of the tree!

Buy an Orion Meter

Optimizing Wood's Use with MC Measurement

One of the most important elements when maximizing wood's performance over time is having an accurate understanding of wood's interaction with moisture.

The first step in preventing moisture-related damage in wood floors and other wood-based building materials is in bringing each wood building product to the correct MC level.

This process begins at the sawmill kilns and carries on through to each finished building application. At each step, it's necessary for accurate MC measurement to determine the wood's final performance.

Free Download - 6 Reasons Your Wood Project Failed

Why the Focus on MC?

Wood is a hygroscopic material. It naturally has a give-and-take relationship with the humidity in the air around it and is always in the process of trying to find a balance between its internal MC and the ambient conditions around it.

On the job site, wood needs to be in balance with its environment, a state referred to as equilibrium moisture content, or EMC. If builders or flooring installers begin the project before wood has adjusted to the relative humidity levels around it, they run the risk of the wood warping, twisting, splitting, or having significant gaps or buckling.

The right tool for monitoring wood MC is a wood moisture meter.

Pin-style moisture meters work in conjunction with the electrical resistance properties of wood by measuring a precise area between the tips of two metal probes or "pins" inserted into the wood. Pinless moisture meters have the advantage of measuring MC along an entire length of a board without causing repeated damage to the wood's surface.

Here at Wagner Meters, our pinless moisture meters are designed with IntelliSense™ Technology, which means MC readings are not susceptible to surface moisture or temperature, and can "scan" wood for MC at a uniform depth without surface damage.

The meters provide easy-to-use, accurate MC measurements to be sure that every building and flooring professional knows the MC of the wood they will be using in the building process.

Overall, wood has some "built-in" advantages when choosing a material with both environmental and aesthetic appeal, and with the right application of wood MC management, wood can retain those properties for generations.

Consider reading, how to use a moisture meter properly next.

(1) http://www.bugwood.org/intensive/wood_s_advantage.html

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The Advantages of Wood as a Building Material

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Wood is obviously both a common and a historical choice as a building material. However, in the past few decades, there has been a move away from wood in favor of engineered products or metals like aluminum.

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Wood is broken down into different chemical elements. The chemical composition of wood varies from species to species. But mostly elements in wood are 50% carbon, 42% oxygen, 6% hydrogen, 1% nitrogen, and 1% other elements (mainly calcium, potassium, sodium, magnesium, iron, and manganese) by weight.

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Builders and manufacturers claim that wood foundations offer a number of advantages like how wood foundations are simpler, quicker and cheaper to construct than masonry foundations like brick or stone

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What is wood?

Structure of wood

Hardwoods and softwoods

Chemical composition

What's wood like?

Strength

Durability

Wood and water

Wood and energy

Environmentally friendly

Using wood

Harvesting

Seasoning

Preserving and other treatment

Cutting

Other wood products

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Advertisement

by Chris Woodford. Last updated: March 16, 2021.

There's plenty of it, it's relatively cheap (or even free), it's environmentally friendly, it looks great, it's warm and cozy, it's super-strong, it lasts hundreds or even thousands of years, and you can use it for everything from building bridges to making paper or heating your home. It's wood-and it's quite possibly the most useful and versatile material on the planet, with many thousands of different uses. So what is it that makes wood so good? Let's take a closer look!

Photo: Wood really does grow on-or rather in-trees. Who'd have thought you could make a lovely coffee table or a fruit bowl from a gnarled old specimen like this? The outer part of a tree trunk might look dead, but it's very much alive: tree trunks grow outward (getting wider) as well as upward (getting higher).

What is wood?

You often hear people grumbling about money and all kinds of other things that "don't grow on trees"; the great thing about wood is that it does grow on trees-or, more specifically, in their trunks and branches.

Structure of wood

Photo: This fence pole was once a tree-and you can still clearly see the annual growth rings if you look down on it from above.

Take a tree and peel off the outer "skin" or bark and what you'll find is two kinds of wood. Closest to the edge there's a moist, light, living layer called sapwood packed with tubes called xylem that help a tree pipe water and nutrients up from its roots to its leaves; inside the sapwood there's a much darker, harder, part of the tree called the heartwood, which is dead, where the xylem tubes have blocked up with resins or gums and stopped working. Around the outer edge of the sapwood (and the trunk) is a thin active layer called the cambium where the tree is actually growing outward by a little bit each year, forming those famous annual rings that tell us how old a tree is. Slice horizontally through a tree, running the saw parallel to the ground (perpendicular to the trunk), and you'll see the annual rings (one new one added each year) making up the cross-section. Cut vertically through a tree trunk and you'll see lines inside running parallel to the trunk formed by the xylem tubes, forming the inner structure of the wood known as its grain. You'll also see occasional wonky ovals interrupting the grain called knots, which are the places where the branches grew out from the trunk of a tree. Knots can make wood look attractive, but they can also weaken its structure.

Hardwoods and softwoods

Wood is divided into two distinct kinds called hardwood and softwood, though confusingly the names don't always refer to its actual hardness or softness:

Hardwoods typically come from broad-leaved (deciduous) trees (those that drop their leaves each fall, also known as angiosperms because their seeds are encased in fruits or pods). Examples include ash, beech, birch, mahogany, maple, oak, teak, and walnut.

Softwoods typically come from evergeen (coniferous) trees (those that have needles and cones and retain them year-round, also called gymnosperms. Examples include cedar, cypress, fir, pine, spruce, and redwood.

Photo: Left/above: Hardwood comes from deciduous trees like this oak. Its leaves (inset) drop off in the fall and new ones grow in spring.

Photo: Right/below: Softwood comes from evergreen conifers, like this pine, which has needles that stay on all year and cones (inset).

It's generally true that hardwoods are harder than softwoods, but not always. Balsa is the best-known example of a hardwood that is actually very soft. Hardwoods have lovely, attractive grains and are used for such things as making fine furniture and decorative woodwork, whereas softwoods often come from very tall, straight trees, and are better suited for construction work (in the form of planks, poles, and so on).

Chemical composition

Look at some freshly cut wood under a microscope and you'll see it's made up of cells, like any other plant. The cells are made of three substances called cellulose (about 50 percent), lignin (which makes up a fifth to a quarter of hardwoods but a quarter to a third of softwoods), and hemicellulose (the remainder). Broadly speaking, cellulose is the fibrous bulk of a tree, while lignin is the adhesive that holds the fibers together.

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What's wood like?

The inner structure of a tree makes wood what it is-what it looks like, how it behaves, and what we can use it for. There are actually hundreds of different species of trees, so making generalizations about something called "wood" isn't always that helpful: balsa wood is different from oak, which isn't quite the same as hazel, which is different again from walnut. Having said that, different types of wood have more in common with one another than with, say, metals, ceramics, and plastics.

Strength

Photo: Trees are strong partly because of roots like these that anchor them in the ground, but also because wood is inherently a strong material. This is the famous Moreton Bay Fig Tree in Santa Barbara, California dates from 1876 and is around 24m (80ft) tall. Photo courtesy of The Jon B. Lovelace Collection of California Photographs in Carol M. Highsmith's America Project, Library of Congress, Prints and Photographs Division.

Physically, wood is strong and stiff but, compared to a material like steel, it's also light and flexible. It has another interesting property too. Metals, plastics, and ceramics tend to have a fairly uniform inner structure and that makes them isotropic: they behave exactly the same way in all directions. Wood is different due to its annual-ring-and-grain structure. You can usually bend and snap a small, dead, tree branch with your bare hands, but you'll find it almost impossible to stretch or compress the same branch if you try pulling or pushing it in the opposite direction. The same holds when you're cutting wood. If you've ever chopped wood with an ax, you'll know it splits really easily if you slice with the blade along the grain, but it's much harder to chop the opposite way (through the grain). We say wood is anisotropic, which means a lump of wood has different properties in different directions.

Photo: Wood is a traditional building material, as popular today as ever. Because wood is anisotropic, natural wooden beams work better as vertical posts (where they are in compression) than horizontal beams (where they are in tension). That's not a problem here, because these beams are laminated so they are equally strong in all directions. The diagonal members add further strength to stop the horizontal beams from bending. Photo by Robb Williamson courtesy of US DOE/NREL (Department of Energy/National Renewable Energy Laboratory). Read more about how buildings work.

That's not just important to someone chopping away in the woodshed: it also matters when you're using wood in construction. Traditional wooden buildings are supported by huge vertical poles that transmit forces down into the ground along their length, parallel to the grain. That's a good way to use wood because it generally has high compressive strength (resistance to squeezing) when you load it in the same direction as the grain. Wooden poles are much weaker placed horizontally; they need plenty of support to stop them bending and snapping. That's because they have lower tensile strength (resistance to bending or pulling forces across the grain). Not all woods are the same, however. Oak has much higher tensile strength than many other woods, which is why it was traditionally used to make the heavy, horizontal beams in old buildings. Other factors such as how well seasoned (dry) a piece of wood is (as discussed below) and how dense it is also affect its strength.

Chart: Wood can be very weak. In tension (for example, stretched horizontally in struts or beams), it's one of the weakest of all common materials. That's why it's more likely to be used in compression (in vertical beams), where it's very much stronger. ( Concrete suffers from the same problem, which it's why it's often reinforced with steel.) All woods are different, and vary with atmospheric conditions, but typically they're 10-30 times stronger in the longitudinal direction than in the radial direction (see the inset picture of a tree trunk for an explanation of these terms).

Durability

One of the best things about wood is how long it lasts. Browsing through the daily news, you'll often read that archeologists have unearthed the buried remains of some ancient wooden article-a wooden tool, perhaps, or a simple rowboat or the remnants of a huge building-that are hundreds or even thousands of years old. Providing a wooden object is properly preserved (something else we discuss later), it will easily outlast the person who made it. But just like that person, a wooden object was once a living thing-and it's a natural material. Like other natural materials, it's subject to the natural forces of decay through a process known as rotting, in which organisms such as fungi and insects such as termites and beetles gradually nibble away the cellulose and lignin and reduce wood to dust and memories.

Photo: Under attack! The big problem with wood is that it's a natural material subject to attack from other natural things, notably fungi and insects. This is what Formosan subterranean termites can do to wood. Photo by Scott Bauer courtesy of US Department of Agriculture/Agricultural Research Service.

Wood and water

Wood has many other interesting characteristics. It's hygroscopic, which means that, just like a sponge, it absorbs water and swells up in damp conditions, giving out the water again when the air dries and the temperature rises. If, like mine, your home has wooden windows, you'll probably notice that they open much more easily in summer than in winter, when the damp outdoor conditions make them swell into the frames (not necessarily such a bad thing, since it helps to keep out the cold). Why does wood absorb water? Remember that the trunk of a tree is designed to carry water from the roots to the leaves: it's pretty much a water superhighway. A freshly cut piece of "green" wood typically contains a huge amount of hidden water, making it very difficult to burn as firewood without a great deal of smoking and spitting. Some kinds of wood can soak up several times their own weight of water, which is absorbed inside the wood by the very same structures that transported water from the roots of the tree to the leaves when the tree was a living, growing plant.

Wood and energy

What other properties does wood have? It's a relatively good heat insulator (which comes in handy in building construction), but dry wood does burn quite easily and produces a great deal of heat energy if you heat it up beyond its ignition temperature (the point at which it catches fire, anywhere from around 200-400°C, 400-750°F). Although wood can absorb sound very effectively (another useful property in buildings, where people value sound insulation shutting out their neighbors), wooden objects can also be designed to transmit and amplify sounds-that's how musical instruments work. Wood is generally a poor conductor of electricity but, interestingly, it's piezoelectric (an electric charge will build up on wood if you squeeze it the right way).

Environmentally friendly

Photo: Wood fuel (a type of biomass) can be an environmentally friendly form of renewable energy. This is a power plant in Burlington Vermont that burns 76 tons of wood chips per hour (left) to make electric power. The wood is mostly grown within 100km (60 miles) of the plant, and a lot comes from wood industry offcuts and logging waste. Photo by Warren Gretz courtesy of US DOE/NREL (US Department of Energy/National Renewable Energy Laboratory).

Wood was one of the first natural materials people learned to use, and it's never lost its popularity. These days, it's particularly prized for being a natural and environmentally friendly product. Forestry is a rare example of something that has the potential to be completely sustainable: in theory, if you plant a new tree for every old tree you cut down, you can go on using wood forever without damaging the planet. In practice, you need to replace like with like and forestry is not automatically sustainable, whatever papermakers like us to believe. A brand new tree has much less ecological value than a mature tree that's hundreds of years old so planting a thousand saplings may be no replacement for felling just a handful of ancient trees. Logging can be hugely environmentally damaging, whether it involves clearcutting a tropical rainforest or selectively felling mature trees in old-growth temperate woodland. Some of the processes and chemicals used in forestry and woodworking are also environmentally damaging; chlorine, used to bleach wood fibers to make paper, can cause water pollution in rivers, for example. But on the positive side, growing trees remove carbon dioxide from the atmosphere and planting more of them is one way to reduce the effects of climate change. Trees also provide important habitats for many other species and help to increase biodiversity (the wide range of living organisms on Earth). Practiced the right way, forestry is a good example of how people can live in perfect harmony with the planet.

Using wood

How does wood get from the tree to the roof of your house, your bookshelf, or the chair you're sitting on? It's a longer and more complex journey than you might think that takes in harvesting, seasoning, preserving and other treatment, and cutting. Here's a brief guide.

Harvesting

Photo: Chopping down a longleaf pine is only the start of the fun: now you've got to get it home preferably without damaging the rest of the forest in the process. That's where this skidder machine comes in, lifting up the logs with a hydraulic crane and dragging them away with a powerful diesel engine. Photo by Randy C. Murray courtesy of US Army.

Growing plants for food is called agriculture; growing trees for human use is silviculture-and the two things have a great deal in common. Wood is a plant crop that must be harvested just like any other, but the difference is how long trees take to grow, often many years or even decades. How wood is harvested depends on whether trees are growing in plantations (where there are hundreds or thousands of the same species, generally of similar age) or in mature forests (where there's a mixture of different species and trees of widely differing ages).

Planted trees may be grown according to a precise plan and clear-cut (the entire forest is felled) when they reach maturity. A drastic approach like that makes sense if the trees are a fast-growing species planted specifically for use as biomass fuel, for example. Individual trees can also be selectively felled from mixed forests and either dragged away by machine or animal or even (if it makes economic and environmental sense) hauled upward by helicopter, which avoids damaging other nearby trees. Sometimes trees have their bark and small branches removed in the forest before being hauled away to a lumber yard for further processing, though they can also be removed intact, with the entire processing done offsite. It all depends on the value of the tree, the growing conditions, how far away the lumber yard is, and how easy the tree is to transport. Another interesting form of forestry is called coppicing, which involves removing long, thin, low-growing branches from trees such as hazel and willow in a careful and respectful way that does no long-term damage.

Photo: These cottonwood trees might look too spindly for making poles or planks, but they'll not be used for either. They're part of a fast-growing plantation that produces biomass, a type of renewable energy burned in power plants. Biomass is better for the environment because the trees take in as much carbon dioxide when they grow as they give out when they're burned; leaving aside the energy wasted in harvesting and processing, a biomass plant produces no overall carbon dioxide emissions, unlike a traditional power plant fueled by oil or coal. Other "energy crops" include willow, poplar, and eucalyptus. Photo by Warren Gretz courtesy of US DOE/NREL (Department of Energy/National Renewable Energy Laboratory).

Seasoning

A freshly cut tree is a bit like a sponge that comes presoaked in water, so it has to be completely dried out or seasoned before it can be used. Dry wood is less likely to rot and decay, it's easier to treat with preservatives and paint, and it's much lighter and easier to transport (typically, half a freshly felled tree's weight may come from water trapped inside). Dry wood is also much stronger and easier to build with (it won't shrink so much) and if a tree is destined for burning as firewood (or an energy crop), it will burn more easily and give out more heat if it's properly dried first. Typically wood is dried either in the open air (which takes anything from a few months to a year) or, if speed is important, in vast heated ovens called kilns (which cuts the drying time to days or weeks). Seasoned wood is still not completely dry: typically its moisture content varies from about 5-20 percent, depending on the drying method and time.

Preserving and other treatment

In theory, wood might last forever if it weren't attacked by bugs and bacteria; preservatives can greatly extend its life by preventing rot. Different preservatives work in different ways. Paint, for example, works like an outer skin that stops fungi and insects penetrating the wood and eating it away, but sunlight and rain make paint crack and flake away, leaving the wood open to attack underneath. Creosote (another popular wood preservative) is a strong-smelling, oily brown liquid usually made from coal-tar. Unlike paint, it is a fungicide, insecticide, miticide, and sporicide: in other words, it works by stopping fungi, insects, mites, and spores from eating or growing in the wood.

Photo: A fence before (right) and after (left) treatment with wood preservative.

Different kinds of treatment help to protect and preserve wood in other ways. It's a great irony that wood can be used to build a fine home that will last many decades or burn to the ground in minutes. Wood is so plentiful and burns so well that it has long been one of the world's favorite fuels. That's why fire-protection treatment of wooden building products is so important. Typically, wood is treated with fire retardant chemicals that affect the way it burns if it catches fire, reducing the volatile gases that are given off so it burns more slowly and with greater difficulty.

Cutting

There's a big difference between a tree and the table it might become, even though both are made from exactly the same wood. That difference comes mainly from skillful cutting and woodworking. How much cutting a tree needs depends on the product that's being made. Something like a utility pole or a fence post is not much more than a tree stripped of its branches and heavily treated with preservatives; that's an example of what's called roundwood. Trees need a bit more work in the sawmill to turn them into lumber, timber, or sawnwood (the three names are often used interchangeably, though they can be used with more specific meanings). Flat pieces of wood can be made from trees by cutting logs in two different directions. If you cut planks with the saw running in lines parallel to the length of the trunk, you get plainsawn (sometimes called flatsawn) wood (with ovals or curves on the biggest flat surface of the wood); if you fell a tree, cut the trunk into quarters, then slice each quarter into parallel planks, you get quartersawn wood (with the grain running along the biggest flat surface in broadly parallel stripes).

Photo: Left/above: Plainsawn wood is parallel to the trunk, revealing the annual rings as curves or ovals. Right/below: Quartersawn wood is first quartered and then sawn, revealing a pattern of roughly parallel lines.

See how attractive those patterns look? Not surprisingly, wood that's destined for furniture and other decorative uses has to be cut much more thoughtfully and carefully with regard to what's called its figure. This is the way a particular tree is cut to show off the growth patterns it contains in the most attractive way in the final piece of wood. The figure can also depend on which part of a tree is used. Wood cut from near the stump of a tree will sometimes produce a more attractive figure than wood cut from higher up.

Other wood products

Photo: Particle board is made from offcuts of wood stuck together and coated with an attractive veneer or other surface layer (perhaps plastic or a laminate). This is what an Ikea Billy bookcase looks like if you peer round the back. You can see the veneer on the extreme left and a hardwood backing on the right.

Roundwood and sawnwood are what you might call natural wood products, because they involve using cut pieces of tree more or less in raw form. There are many other ways of using trees that involve greater amounts of processing. Some woods are very rare and expensive, while others are cheap and plentiful, so a common technique is to apply an outer layer of expensive and attractive wood to a core of cheaper material. Veneer is a thin decorative layer applied to cheaper wood made by turning a log against a blade, much like peeling an apple. Using veneer means you can get an attractive wooden finish at much lower cost than by using a solid piece of expensive wood. Plywood is made by taking layers of wood (or plies) and gluing them together with an outer coating of veneer. Typically each ply is placed at 90 degrees to the one underneath so the grains alternate. That means a piece of plywood is usually much stronger than a piece of the natural wood from which it's made. Laminated wood is a weaker kind of plywood in which the grain of each layer runs in the same direction. Particle board (often called chipboard) is made by taking the waste chips, flakes, and sawdust from a mill and forcing it under high pressure, with glue, in a mold so it sticks together to make planks and panels. Low-cost and self-assembly furniture is often made this way. Fiber-board is similar, but made with wood-pulp fibers instead of wood chips and sawdust. Hardboard is a thin sheet of wood made from wood fibers in much the same way.

Not all wood products are immediately recognizable as such. A great deal of the paper and cardboard people use is made by turning cellulose from trees into a fibrous pulp, for example. Lignin (the other main chemical inside wood) also has many uses, including making plastics (such as the celluloid used in old-fashioned photographic film), paints, turpentine, and yeast products.

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On this website

Books

General

Practical and technical

Materials science

For younger readers

The Wonder of Trees by Nicola Davies and Lorna Scobie. Hodder, 2019. A wide-ranging, 64-page, illustrated celebration of trees, including a closer look at the structure of a tree, ecosystems based on trees, and environmental issues such as deforestation. Ages 9-11.

DK Eyewitness: Tree by David Burnie. Dorling Kindersley, 2015. A lavish, 72-page photographic guide that follows the basic science of how trees grow from seeds to saplings, how they're affected by things like pollution, and how to recognize a few of the more common species. Ages 9-12.

Wood by Steve Parker. Gareth Stevens, 2001. This book has more of an emphasis on wood as a material. Topics covered include where wood comes from and why it's important in everyday life. Ages 9-12.

Articles

Five Stories Tall and Made of Wood by C. J. Hughes. The New York Times, 17 January 2020. Renewed interest in timber-framed buildings reflects our climate-conscious times.

The Trees and the Forest of New Towers by Stephen Wallis. The New York Times, 20 November 2019. Is traditional timber the future of eco-friendly buildings?

Let's Fill Our Cities With Taller, Wooden Buildings Frank Lowenstein, Brian Donahue and David Foster. The New York Times, 3 October 2019. Wooden buildings are the future, the authors argue, because they're a form ofcarbon capture and storage.

Tracking timber: could new technology help clean up the supply chain? by Will Henley. The Guardian, 14 August 2013. Monitoring the origin of timber using techniques such as DNA testing offers a practical way of protecting forests.

Recycled wood: the truly green key to a sustainable built environment by Leon Kaye. The Guardian, 24 July 2012. Using reclaimed timber saves forests and keeps waste out of landfills.

Building With Whole Trees by Anne Raver. The New York Times, November 4, 2009. Architects are exploring the advantages of building with more or less intact trees (instead of ones stripped down into anonymous planks and beams).

Evaluating the Environmental Performance of Wood Building Materials by Jason Guiles. State University of New York College of Environmental Science and Forestry. A short but very informative summary of how wood compares to steel, concrete, and other heavy-duty building materials.

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Wood - An introduction to its structure, properties, and uses

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Advertisement by Chris Woodford. Last updated: March 16, 2021. There's plenty of it, it's relatively cheap (or even free), it's environmentally friendly, it looks great, it's warm and cozy, it's super-strong, it lasts hundreds or even thousands of years, and you can use it for everything from building bridges to making paper or heating your home.

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https://hyperallergic.com/62369/the-worlds-oldest-wooden-architecture/

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https://www.fs.usda.gov/learn/trees/anatomy-of-tree

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In this article we'll explore and detail the benefits of wood based designs. This article isn't going to exclusively revolve upon wooden houses, but also the use of wood within designs and construction. Wood is a wondrous material; hopefully you'll agree upon conclusion of this article.

1. Exceptional Insulator & Energy Saver

Some building materials such as steel, inorganic materials which are non-combustible, expand when heated which can weaken and collapse the structure. Wood reacts in an almost opposite manner to this. When heated (not excessively to a combustible temperature of course), wood dries and actually becomes even harder.

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Let's make some comparisons here. Glass conducts heat 23 times faster than wood, marble 90 times faster, steal 1650 times faster and aluminium a whopping 7000 times faster.

This means less energy 'leakage' from a home. If you want the warmth (or coolness) to remain in your home, and you want to spend less money on heating (or cooling), wood is a tremendous alternative to brick, concrete or stone. Compared to other construction materials, wood, economically is a star child of insulation.

In brief: Using wood saves on heating bills and using wooden frames within structures is thrifty.

Fact: Wood actually does expand slightly when air humidity drops below 0%, however this won't affect the constructors amongst us as even in the most parchedness of climates, humidity doesn't drop below 5%.

2. Quick to Build: Saves Money
"People love chopping wood. In this activity one immediately sees results." Albert Einstein. Looks like he hit the nail on the head there. People like quick inexpensive results, and that's exactly what wood can offer.

Some wooden home manufacturers can construct a 100m² wooden house, on site within 7 days. Imagine popping to Florida for a two week vacation, returning home to discover a new building has sprung up in your neighbours garden. I told you wood was impressive!

When compared with brick, stone or concrete, wood constructions certainly do save time, and inherently with that come savings in labour. This is especially applicable in harsh weather conditions such as heavy rain, snow and icy conditions, where wood construction can continue without hindrance. It has also been said from a builder friend of mine that plans for wooden structures are easier to follow than brick, concrete or using steel frames (feel free to comment on this in the comments section as I don't know the validity of this comment).

Wood-framed houses enable easy modifications during and after the building process and it's because of the ease, versatility and cost effectiveness which makes it such a popular and inexpensive choice. Insulated concrete form homes (ICF) can be costly, troublesome and time consuming to alter post build.

Mint Images / Getty Images

3. Environmentally friendly

Green is the big thing these days so of course this is going to be a big feature in this article. Houses made from trees are sustainable, renewable and environmentally friendly. Did you know that wooden structures absorb and store atmospheric CO2 and that wood, even taking into account haulage, is carbon neutral (in fact, it's the only carbon neutral construction material).

Fact: 0.8 tonnes of carbon emissions are saved for every cubic meter of wood which is used in construction, therefore, if a home uses 20 cubic meters of wood, that's a saving of 16 tonnes in carbon. In context, 16 tonnes of carbon is the same amount of carbon produced by driving 90,000 kilometers (as a very crude estimate). Using wood in construction, whether it's a complete construction of just the wooden frames, really does have a positive impact on climate change.

Most westernized countries have legislation where at least one tree has to be planted for every tree which has been cut. This is significant because it means there will be more wood on the planet, which means more carbon absorption. Let us not put our blinders on though, deforestation is a despicably saddening fact, therefore make sure your source of wood isn't questionable.

Mature trees actually use absorb less carbon than younger, faster growing trees, therefore it could be beneficial in the battle on climate change to cut the older trees, use them in construction and plant new carbon munching trees in their place.

4. Aesthetically Acrobatic

With over 5000 different woods to choose from, there is absolutely going to be something that'll suit ones construction or design desires. Some woods are ideal for insulation, some for acoustics, grain, color, appearance, and others for structural frames, walls, floors, ceilings and furniture.

In my personal opinion, the grain on a piece of wood is one of the most mesmerizing beauties in the natural world, where different hues of color and textures roll back into each other like an enchanting dance. I'm not over embellishing it either. Some of the most breath taking architectural designs are wood centered.

Wood can be painted in any color and can be waxed and varnished which'll brandish its natural finesse. It can be carved, cut, glued and nailed.

Wood is so versatile and aesthetically delightful, the only limit to what one can make with it is restricted by ones imagination. Just like Albert Einstein has said, 'Imagination is more important than knowledge' and, 'Imagination is everything. It is the preview of life's coming attractions'. Here's my own personal spin on that quote, 'Imagination is everything. It is the preview of remarkable designs and engineering feats, yet to be materialized'.

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5. Mechanical Properties & Working Properties

A few months ago, in conversation with a horticultural friend of mine, I was discussing a taxus baccata (European yew) hedge with him; what he likes to call, 'Taxus baccata is the hedge with the edge'! We progressed onto the topic of wood density. I always knew the taxus baccata was a very hard wood because it only grows about 5cm per annum, but I wondered whether it was harder than oak. This led me to the 'Janka' hardness test which measures how resistant the wood is to denting and wear.

To test the hardness of a given wood, the test measures the force required to embed an 11.28mm steel ball half way into the wood. It turns out that the yew requires 1500 pounds of force while oak fall just shy at around 1300 lbs.

I've said all that to illuminate ones perspective of the incredible variety of properties wood can have, which could inspire one to investigate new types of wood in upcoming projects. What's the hardest wood I hear some say, well that would be the Australian Buloke which requires 5060 pounds of force. One of the softest woods is from a cuipo tree, which requires 22 pounds of force, far softer than the better known balsa wood which comes in at 100 lbs.

I'm going to get even more technical on you now so skip this if it doesn't tickle you. Wood, although light has a remarkably high tensile strength. Let's take wood which has a tensile strength of 0,6/cm3 and the specific gravity is 100 N/mm2, as well as steel which has a tensile strength of 7,89/cm3 and the specific gravity is 500 N/mm2.

If we divide the tensile strength by the gravity, the given figure will tell us the quality of the material and its breaking length. The 'breaking length' means the point at which the material breaks under its own weight. Steel which is used in buildings has a breaking point of 5.4km and hardened bow steel 17.5km.When we compare the tensile strength of steel to two varieties of wood, spruce and laminated beech, the respective breaking lengths are 19.8km and 28.3km. Now you know why laminated wood is used on the floors of sports halls!

When it comes to how workable wood is, few things can surpass it. Wood can be whittled in beautiful and creative ways, which can make for almost magical designs. The accuracy and finish that can be achieved with wood can help carve an ordinary design into something extraordinary. Further to that, wood is fairly easy to maintain and to repair, so if it goes wrong, fixing the problem won't burn a too big of a hole in ones wallet.

6. Safe, Light, Sturdy & Durable

One of the many reasons why wood is still used today, despite huge strides in engineering excellence, is its durability weight and safety. Wood has a little bit of give in it which means it can bend slightly, which is a property which bricks don't have. Therefore, if the foundations shift slightly, the wooden home can flex and move with the change rather than crack. Even the smallest shift in the foundations of a brick house will case cracks to appear in the mortar (not a good look).Talking about foundations, one reason that most of the houses in the south east of the USA are wooden is because the soil is weak. Heavy brick can cause the ground to sink, therefore light wooden houses are preferred; nobody wants to become the victim of a sink hole.

Back to cost again here, but in a similar vain of thought, wooden houses are prevalent (and sometimes required) in the south east because they are cheaper to rebuild if destroyed by a hurricane. It seems a category 5 hurricane will destroy a brick build as well as a wooden one.

Westend61 / Getty Images

7. Water Resistant

While many woods soak in moisture and water, causing them to swell, there are some varieties of wood which are highly water resistant. A study has been conducted into the absorption rates of of four different varieties of wood, Western Red Cedar, Douglas Fir, Western Hemlock and Sitka Spruce. The woods were dried so that their moisture content ranged from 6-10% and were then left outside, covered. After one year, the moisture level of Western Cedar was between 9-11%, while the others ranged between 14-21%. The increase in moisture absorption from the untreated cedar wood was minimal.

This study demonstrates that even though some woods have a tendency to absorb moisture, there are particular varieties of wood which will not have that tendency. I'm sure there are some woods which are used specifically for their high absorption rates, and some, such as cedar for their low absorption rate.

Mint Images / Getty Images

8. Healthy & Natural

Electrostatic charge: This is a big deal for some people as electrostatic charges are believed to be unhealthy to some degree. Good news folks, wood emits zero electrostatic charge; nada, zilch!

If a room is finished with an uncoated wood, it'll help regulate the humidity which could aid in helping people with respiratory sensitivity. Not only does it regulate humidity, just the mere look of wood can sooth ones mind and relax the nervous system (so I've heard!). Just make sure the humidity doesn't make the wood too moist, otherwise that static electricity benefit could be thrown out the window.

For these reasons, wood is deemed to be a healthy choice over metal, plastic and other materials.

asbe / Getty Images

9. Acoustically Sound

Even though wood doesn't act as a perfect sound insulator, it does prevent echoes from bouncing around the room by absorbing sound waves. When compared to its constructive competitors, wood proves to be much more effective at sound insulation, especially when it comes to insulating between different rooms.

Wood is also used in many concert halls around the world as it naturally dampens sound, creating that perfect tone within the room.

EyeEm / Getty Images

10. Rust be Gone

Last but not least, wood doesn't rust. Even though it can oxidize in some form, it is statistically insignificant when compared with metal. True, there are some metals that don't rust, but they're more expensive; and can you really criticize wood after we've learned how wonderful it is!

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Timber Architecture: 10 Benefits of Wood Based Designs

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In this article we'll explore and detail the benefits of wood based designs. This article isn't going to exclusively revolve upon wooden houses, but also the use of wood within designs and construction. Wood is a wondrous material; hopefully you'll agree upon conclusion of this article.

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Wood has healing properties relative to the human body, as it removes stress and discontent, restores the nervous system, improves sleep quality, increases physical activity and creative thinking. Even the color of wood can affect on the human psychological health.

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Residents in aged care facilities interact more with each other when surrounded by wood.

Students in classrooms that feature more wood have lower heart rates and stress responses than students in classrooms featuring plastic and metal.

Two out of three workers prefer offices with wooden chairs, desks and blinds over the same office with those items made from plastic.

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Timber is naturally an insulating material that creates a barrier between heat and cold.

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During the event of a fire, a charcoal layer will be formed on the surface of the timber and this layer will contribute to the fire resistance of the material. The charcoal layer insulates the inner core of the timber and it will slow down the heat penetration, keeping the temperate in the unburned material low and enabling the timber to carry its load much longer than steel. The protective charcoal layer created during a fire will also reduce the overall combustion rate of the timber. This natural self-defence mechanism increases the possibility for a timber structure to survive a fire while maintaining its strength and stability.

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being surrounded by wood in your home, work or school has positive effects our health.

Improved emotional state, and self-expression

Improved air quality by moderating humidity, encouraging easier breathing

Feelings of warmth and comfort

Lower blood pressure, heart rate, and stress levels

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natural, renewable building materials.
contribute to the long term reduction of carbon emissions - less environment impact
a natural way to store carbon
uses less fossil fuel energy

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The Benefits of Using Wood

Timber is one of the few natural, renewable building materials. The cyclical process involved in the harvest and regeneration of forests for timber production ensures that timber will continue to be available. Every time a tree is harvested, up to ten trees are re-established in its place; the renewable cycle begins again. Being a natural resource, timber is not toxic, and is safe to handle and touch; it also ages naturally and does not break down into environmentally damaging material.

In keeping with their environmental commitments, Hyne Timber's treatments are all organic, keeping their timber environmentally-friendly.

Timber is a greenhouse positive product with a lower net environmental impact than most other building materials, such as emission-intensive steel, aluminium, or concrete. It's one of the only building materials that contribute to the long term reduction of carbon emissions: positively addressing climate change.

Carbon is an elemental building block of all living things on earth. As a forest grows the trees absorb atmospheric carbon dioxide and store it in their leaves, branches and trunks. Approximately half the dry weight of a living tree is carbon, stored for the life of the tree, and retained throughout the timber manufacturing process.

In 2015, Australia built 115,989 detached houses. If all of those houses were timber framed, it would equal a total of 1,159,890 tonnes of carbon dioxide as the harvested plantations are replanted and begin the cycle of carbon retention all over again.

The process of manufacturing timber uses substantially less fossil fuel energy per unit volume than steel, concrete, or aluminium: minimising the amount of pollutants created during the process. This means that building with one cubic meter of wood, in place of other construction materials like concrete, blocks, or bricks, can save up 0.75 to 1 tonne of CO2 emissions.*

* Source: Using wood products to mitigate climate change: A review of evidence and key issues for sustainable development (January 2004), International Institute for Environment and Development (IIED) and The Edinburgh Centre for Carbon Management (ECCM).

MATERIAL
Sawn Timber
Concrete
Steel (virgin)
Aluminium

FOSSIL FUEL ENERGY (MJ/kg)
1.5
2
35
435

FOSSIL FUEL ENERGY (MJ/m3)
750
4,800
266,000
1,100,000

World studies have shown that being surrounded by wood in your home, work or school has positive effects our health. A recent report commissioned by Planet Ark has found that exposure to wood products and interiors created similar health benefits to those created by spending time in nature. The report also including survey findings that reflected Australians are "innately drawn towards wood".

Some of the reported health benefits include:

Improved emotional state, and self-expression

Improved air quality by moderating humidity, encouraging easier breathing

Feelings of warmth and comfort

Lower blood pressure, heart rate, and stress levels

Australians spend over 90% of their time indoors; bringing nature inside is a positive step to a healthier future, for you and the environment.

Yes, timber is a combustible material but it burns in a slow, predictable and measurable way. These factors mean that timber actually performs strongly in fire events, when compared to other materials.

During the event of a fire, a charcoal layer will be formed on the surface of the timber and this layer will contribute to the fire resistance of the material. The charcoal layer insulates the inner core of the timber and it will slow down the heat penetration, keeping the temperate in the unburned material low and enabling the timber to carry its load much longer than steel. The protective charcoal layer created during a fire will also reduce the overall combustion rate of the timber.

This natural self-defence mechanism increases the possibility for a timber structure to survive a fire while maintaining its strength and stability.

Timber is naturally an insulating material that creates a barrier between heat and cold.

The secret can be found in the many air pockets within the cellular structure of timber products, meaning that light weight timber is a better insulator as thermal conductivity increases with density.

Construction design with a focus on energy efficiency through lightweight timber can greatly contribute to maximising comfort and minimising non renewable energy use. In addition, timber framed buildings can allow for extra insulation materials to be placed in spaces between framing members without increasing wall, ceiling, roof or floor thickness. The natural thermal properties of timber also maximise the efficiency of insulation materials as wood will not become cold or dissipate heat, therefore requiring less energy to maintain warmth throughout a building.

Download the 'House, Health, Humanity' report from Planet Ark to get a more in depth understanding of the health and wellbeing benefits of wooden interiors in homes, businesses, places of learning and places for healing. It also includes the results of an independent survey which identifies the attitudes and opinions of Australians on wood.

Some of the findings include:

Residents in aged care facilities interact more with each other when surrounded by wood.

Students in classrooms that feature more wood have lower heart rates and stress responses than students in classrooms featuring plastic and metal.

Two out of three workers prefer offices with wooden chairs, desks and blinds over the same office with those items made from plastic.

Download

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Wood reduces stress and and positive effects on body

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Wood reduces stress and and positive effects on body

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"Based on studies carried out so far, we can say that wood reduces stress in a person and has a calming effect. This is based on the positive emotional experience that wood causes, such as proximity to nature, warmth, homeliness and a relaxing effect,"

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Based on studies carried out in Norway, Japan, Canada and Austria, wood seems to have positive effects on the emotional state of people. Environments with wooden structures cause a drop in blood pressure and pulse and have a calming effect. "Now that we are very familiar with the technical properties of wood, we should carry out a cross-disciplinary research project about the psychological and physiological effects of wood," suggests Wallenius.

But what factors in wood as a building material affect people? "Wooden surfaces make a room feel warmer and cosier and they also have a calming effect. In these properties, wood beats all other normal surface materials," answers Wallenius.

The answer to the question 'what is a good material for people?' is sought through human experience and how this positive experience manifests itself physiologically and psychologically. "One answer is the naturalness of wood, which is also found in all other natural materials such as rock, linen and silk. The naturalness and natural origin of wood is also why wood is considered a warm and cosy material in construction," says Wallenius.

According to observations made in research, touching a wooden surface gives people a feeling of safety and being close to nature. "It is especially interesting that the feel of wood is softer than other materials, not only experientially but also physiologically," says Wallenius.

In studies, for example, touching aluminium at room temperature, cool plastic or stainless steel caused a rise in blood pressure. Touching a wooden surface, however, did not cause such a reaction. In a comparison of different work rooms, stress level, measured as the skin's capacity to conduct electricity, was lowest in a room with wooden furniture. Not even plants brought into a room fitted out in white had the same effect.

Research results encourage new innovations in the wood products sector

In Wallenius' opinion, a research objective is to put results into practice and utilise companies, for example in marketing. "This would give the wood processing industry quite new dimensions. Company management also needs to be bold in devising new innovations. Boundaries between the sciences and humanities should also be torn down.

"Continuing this research is also important because questions regarding indoor air are becoming increasingly important social issues in public facilities and housing. The use of wood may affect not only air quality and acoustics but also the atmosphere of a room and the mood and physiological stress level of those present there."

Wallenius says that as people are psycho-physical entities, the psychological experience is also reflected in physiology. The health effect comes when the psychological experiences changes into a physiological reaction. It is thus advisable to examine the psycho-physical effect of the use of wood, because the psychological and physiological effects are inseparable.

Changes of mood such as their emotional states are at the same time manifested in bodily changes. For example, stress is not only an experience. It is also a large number of physiological and cognitive changes. Autonomous nervous system indicators such as fluctuation in heart rate also reflect the balance of a person's system more broadly.

"Based on studies carried out so far, we can say that wood reduces stress in a person and has a calming effect. This is based on the positive emotional experience that wood causes, such as proximity to nature, warmth, homeliness and a relaxing effect," explains Wallenius.

This article has been reprinted with kind permission of www.woodproducts.fi

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Wood construction reduces stress and offers a healthy living environment

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Based on studies carried out in Norway, Japan, Canada and Austria, wood seems to have positive effects on the emotional state of people. Environments with wooden structures cause a drop in blood pressure and pulse and have a calming effect.

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It's a renewable material

It lasts a long time

It can be recycled and reused

It absorbs carbon dioxide

It's great at retaining heat

Its waste is biodegradable

It has a positive effect on your physical and mental health

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What could wood do?

Be the one who branched out.

The aesthetic, biophilic, and other benefits of using wood offer market differentiators that can boost a project's overall value.

Wood can contribute to a project's sales proposition and create warm, beautiful environments that appeal to a new generation of eco-minded employees, residents, and occupants. Some builders and developers have reported higher sales, rental, and/or lease rates for wood buildings compared to similar non-wood structures.

One-to-Four Story Office Buildings Can Cost

per square foot than their non-wood counterparts.

A comparative analysis of one-to-four story office buildings constructed between 2009 and 2015 conducted by WoodWorks shows that wood offices can cost 20 to 30 percent less per square foot than their non-wood counterparts.

Money grows on trees.

The developer for Clay Creative, a timber office building in Portland, Oregon, reports that tenants were willing to pay $7 more per square foot than a similar non-wood structure located across the river downtown.

Clay Creative

Photo: Christian Columbres | Mackenzie Architects

View project

Wood is a sustainable, high-value building material. Building with wood is efficient, often completed faster than other systems, and can be done year-round in almost any climate. Wood can often be locally sourced from North American forests and is frequently less expensive than alternative building materials. It is readily available and tends to be delivered faster than other materials.

New Energy Works Tomorrowland interior

Wood do anything for you.

Wood is also well suited to additions and retrofits. Wood systems can be dismantled with relative ease, and the materials can be used elsewhere.

Templar Flats

Photo: Industryous Photography | Lintack Architects Inc.

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Efficiency experts.

Our members are trained, skilled, and ready to work."

WoodWorks Contractor Training

Is your team ready for a changing built environment? Get trained for mass timber.

As many cities grapple with an affordable housing crisis, wood can play an important role by improving access to economical, comfortable, and safe living spaces.

U of W Mercer Court / Elm Hall

Photo: Benjamin Benschneider | Mahlum Architects

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Bio-feeling good!

This has led to an increase in the use of materials like wood as a key element of biophilic and evidence-based design. Evidence suggests people feel a sense of well-being when exposed to wood in a building , and many designers cite the warm and natural attributes of wood as a reason for its use.
Want to know why we feel good with wood? Read this white paper.

Bring the outside inside with these biophilic design tips.

TRANSFORMING WHERE WE LIVE AND WORK

Population growth, environmental changes and urban expansion are putting pressure on our cities and our planet's resources. Wood is a smart choice for cities and our future. Whether solving for urban density, sustainability, or climate resilience, wood construction can help solve the issues our cities face today and in the decades to come.

Need lumber support? We can help.

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Benefits of Using Wood in Construction | Think Wood

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What could wood do? Be the one who branched out. The aesthetic, biophilic, and other benefits of using wood offer market differentiators that can boost a project's overall value. Wood can contribute to a project's sales proposition and create warm, beautiful environments that appeal to a new generation of eco-minded employees, residents, and occupants.

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Wood, a good way to save the environment

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Wood, a good way to save the environment

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https://www.forestfoundation.org/wood--a-good-choice-for-energy-efficiency-and-the-environment

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Family-owned forests provide 50% of the wood that flows into the U.S. supply chain.

The majority of forests in the United States are family-owned, so it's no surprise that family-owned forests are critical to our nation's wood supply.

Research from the American Forest Foundation, produced in partnership with the U.S. Forest Service and the Family Forest Research Center, shows that family-owned forests currently house more than 358 billion cubic feet of standing wood-which can be used to heat and supply energy for American homes.

What it means to be sustainable

Sustainably produced wood comes from forests that are managed for a full range of benefits and functions-where forest owners work to protect clean water and wildlife habitat, replant after harvesting, and promote diversity while combating invasive species. These actions ensure that forests stay as forests and continue to produce benefits well into the future.

For more information on sustainability and third-party certification, check out the American Forest Foundation's American Tree Farm System,® our longstanding network of 69,000 family forest owners sustainably managing 18 million acres of forestland in the United States.

The American Forest Foundation is working across the country to engage landowners in sustainable forest management practices.

As one example, we've partnered with a diverse group of universities, government agencies, conservation organizations and industries to support the White Oak Initiative whose mission is ensuring the long-term sustainability of America's white oak forests.

Learn more about partnering with us to support family forest owners in sustainable forest management practices and ensure the long-term sustainability of our nation's wood supplies.

AFF Launches Pilots in GA, SC and FL to Grow ATFS Certification Three-Fold

For family landowners, being certified in ATFS validates good forest stewardship and provides access to free or reduced professional resources to help them care for their land. For some, however, the certification process can be long and slow. In fact, across the U.S., fewer than 10% of family lands in the U.S. are certified. Starting this year, AFF is launching pilot programs in South Carolina, Georgia, and Florida, which will aim to increase the growth rate of certified acres by three times its current pace annually.
Read More

AFF Helps Family Forest Owners Make Significant Contribution to Longleaf Restoration

The American Forest Foundation (AFF), a long-time participant in the ALRI coalition, is proud to have supported one of the most significant non-profit contributions to these results - 23,000 acres - to longleaf restoration. Through its work, AFF is facilitating more family forest owners be a part of the solution and make important contributions to biodiversity and wildlife needs.
Read More

Dutch Biomass Certification Foundation Enlists AFF to Help Reach Its Sustainability Goals

The American Forest Foundation (AFF) recently announced that it has received $1.5 million in funding over three years from the Dutch Biomass Certification Foundation (DBC) for its sustainability assurance work. DBC is a non-profit entity that was established to promote certification and provide support to small forest owners in North America, where the majority of the country's wood biomass supply is sourced.
Read More

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The majority of forests in the United States are family-owned, so it's no surprise that family-owned forests are critical to our nation's wood supply. Research from the American Forest Foundation, produced in partnership with the U.S.

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How do wood sky-rises work? How are they made?

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How do wood sky-rises work? How are they made?

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https://www.wired.com/story/building-high-rises-out-of-wood-can-help-save-the-planet/

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To get these figures, the researchers did a whole lot of scaling up. They used accepted figures for the emissions involved in making a ton of steel or concrete, and the emissions you'd sequester by producing a ton of timber. Then they scaled that up to how much material you'd need for a building, then scaled it up to how many materials you'd need per capita to build new structures. The team accounted for population growth, as well as the increasing demand for space as people around the world ascend into the middle and upper classes.

"This transition is feasible under two conditions: That the harvested forests are sustainably managed, and that the carbon that is transferred from forests into the cities and stored in the buildings is preserved in some form after demolition of buildings," says Churkina. That is, we can't just go chopping down forests willy-nilly, and we can't just burn the buildings after we tear them down-that'd just put the carbon right back into the atmosphere. Instead, that wood needs to be recycled, for instance as floorboards in new homes.

Now, we're not just talking about cobbling together a 20-story building out of mere two-by-fours. Modern timber high-rises make use of cross-laminated timber, essentially large-scale plywood, made by gluing two-by-fours together into a sheet, then flipping the sheet 90 degrees and gluing still more two-by-fours on top. "You end up with a basically a sheet of wood that is, in its size and the way you use it when you engineer or design with it, very similar to a slab of concrete," says Michael Ramage, director of the Centre for Natural Material Innovation at the University of Cambridge, who wasn't involved in this new work. "It just weighs one fifth the amount." (Keep that weight factor in mind-it'll be important later when we talk safety.)

As an analog for steel, architects also use glue-laminated timber. It's the same principle, only the end product is beams instead of sheets. These can support a structure, and architects can even bend them to craft flourishes like domes.

The beauty of both cross-laminated and glue-laminated timber is that they leverage the pound-for-pound strength of wood while getting rid of some of its organic weaknesses. In the manufacturing process, each component piece of timber is scanned for imperfections, like knots, that could weaken the material, which are cut out before the pieces are glued together.

In the last couple of decades, the manufacture of these kinds of composites has, ironically, turned an ancient building material into what's really the only new structural material in the last century, says Ramage. "You have to go back to basically reinforced concrete and emergence of structural steel, both at the end of the 19th century, for a new structural material at the scale of buildings."

Still, these newfangled materials inherently limit the scale of wooden buildings. A 10-story steel building weighs two or three times as much as a wooden version. "Because of that, as you get higher, wooden buildings counter-intuitively have to be stiffer than steel or concrete," says Ramage. This is your fault as a human, really: Buildings have to sway in the wind or earthquakes so they fail, but they can't sway too quickly, or they'll make their occupants seasick. Because wooden buildings are so much lighter than ones made of steel and concrete, they move much faster in the wind.

"It's not even the amount of movement, it's the speed of movement that we're susceptible to," Ramage adds. "It's like being on the rocking deck of a ship." Accordingly, architects have to design these lighter wooden buildings to be stiffer than traditional skyscrapers-but not too stiff, or they'll fail in the wind. That limits how high they can go. But there's an upside: Because timber buildings are made of lighter stuff, workers can assemble them faster, saving the client money. (The cost of the laminated materials remains high, but prices are coming down.) They don't have to weld steel beams and pour concrete.

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Building High-Rises Out of Wood Can Help Save the Planet

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To get these figures, the researchers did a whole lot of scaling up. They used accepted figures for the emissions involved in making a ton of steel or concrete, and the emissions you'd sequester by producing a ton of timber.

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When the natural position of the stem of a tree is disrupted by gravity or something that causes stimuli it causes the wood to bunch up and compress which changes the shape and thickness

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Wood decay doesn't decay because it gets wet. It decays because it been attacked by temperatures, fungi, or special conditions of moisture.

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If you compared the weight of wood and an equal amount, or volume, of water the sample of wood would weigh less than the sample of water. This means that wood is less dense than water. Since wood is less dense than water, wood floats in water, no matter how big or small the piece of wood is.

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Architects, builders, and sustainability advocates are all abuzz over a new building material they say could substantially reduce greenhouse gas (GHG) emissions in the building sector, slash the waste, pollution, and costs associated with construction, and create a more physically, psychologically, and aesthetically healthy built environment.

The material is known as, uh, wood.

Trees have been used to build structures since prehistory, but especially after disasters like the Great Chicago Fire of 1871, wood came to be seen as unsafe and unstable relative to the two materials that have since become staples of the construction industry worldwide: concrete and steel.

However, a new way of using wood has put the material back in the spotlight. The hype is focused on structural timber or, as it's more popularly known, "mass timber" (short for "massive timber"). In a nutshell, it involves sticking pieces of soft wood - generally conifers like pine, spruce, or fir, but also sometimes deciduous species such as birch, ash, and beech - together to form larger pieces.

Yes, the hottest thing in architecture this century amounts to "wood, but like Legos."

Mass timber is a generic term that encompasses products of various sizes and functions, like glue-laminated (glulam) beams, laminated veneer lumber (LVL), nail-laminated timber (NLT), and dowel-laminated timber (DLT). But the most common and most familiar form of mass timber, the one that has opened up the most new architectural possibilities, is cross-laminated timber (CLT).

To create CLT, lumber boards that have been trimmed and kiln-dried are glued atop one another in layers, crosswise, with the grain of each layer facing against the grain of the layer adjacent. Stacking boards together this way can create large slabs, up to a foot thick and as large as 18-feet-long by 98-feet-wide, though the average is something more like 10 by 40. (At this point, the size of slabs is restricted less by manufacturing limitations than by transportation limitations.)

Slabs of wood this large can match or exceed the performance of concrete and steel. CLT can be used to make floors, walls, ceilings - entire buildings. The world's tallest mass timber structure, at 18 stories and over 280 feet, was recently built in Norway; there's an 80-story wooden tower proposed for Chicago.

I talked to lots of people who are extremely excited about mass timber, both for its architectural qualities and for its potential to help decarbonize the building sector, and a few raised important cautions. We'll run through all the advantages and caveats in a moment. But first, let's take a quick spin through the history of mass timber and where it currently stands.

Mass timber is (finally) coming to America

CLT was first developed in the early 1990s in Austria, where softwood forestry is extremely common. It was championed by researcher Gerhard Schickhofer, who is still active and who won a prestigious forestry prize last year for his work to standardize and secure popular support for the new material.

In Austria and in Europe generally, where it spread in the 2000s, CLT was developed for use in residential construction. Europeans do not like the flimsy wood stick-frame construction used for so many US houses; they prefer more solid materials like concrete or brick. CLT was meant to make residential construction more sustainable.

But in the US, CLT can't (yet) compete with stick-frame construction, which is cheap and ubiquitous. It wasn't until North American architects got the idea of using CLT in bigger buildings, as a substitute for concrete and steel, that it began popping up in North America in the 2010s.

In 2015, CLT was incorporated into the International Building Code (IBC), which jurisdictions across the US adopt as their default. A set of new changes that will enable mass timber structures up to 18 stories tall have been accepted and are expected to be formalized into the newest IBC code in 2021.

Some jurisdictions in the US have been aggressive about supporting mass timber, including Washington and Oregon (which have preemptively accepted the new changes to the IBC; Oregon incorporated CLT as a " statewide alternative method " in 2018).

The Pacific Northwest is understandably excited about a possible shift to wooden building materials, as it is home to copious forests and idled sawmills.

"Timber harvest in [the Pacific Northwest] has declined significantly as a result of the weak domestic demand during the housing crisis, which has been devastating to the forest products industry," reports a recent study of CLT lifecycle emissions. "In Washington State, the volume of lumber produced declined 17% between 2014 and 2016 and, compared to 10 years ago, lumber mills (the largest sector by timber consumption) produced one third fewer boards."

Nationally, forests are so overstocked that the Forestry Department is giving out $9 million in grants for new ideas for how to use wood. Plenty of local communities would welcome new demand.

While CLT is continuing to explode in Europe and is accelerating in Canada, it remains hampered in the US by anachronistic and overly prescriptive building codes, limited domestic supply, and the small-c conservative thinking of the building trades.

On the supply front, Vaagen Brothers, a well-known Washington sawmill, has already spun off a second company focused on CLT; other mills are expected to follow suit. A company called Katerra recently opened the largest CLT manufacturing facility in North America in Spokane, Washington, with state lawmakers on hand to celebrate. That may help mass timber get going in earnest in the region.

For now, there are a number of flashy one-off CLT projects in the US: the Catalyst innovation hub in Spokane, the T3 office building in Minneapolis, the Carbon 12 condominiums in Portland, Oregon, Franklin Elementary School in West Virginia, and more. But because they are one-offs, they require a lot of extra work in testing, designing, and securing permits. And there's a shortage of both suitable materials and contractors and builders familiar with them. "It's not a mature industry," says architect Michael Green, whose seminal 2013 TED Talk on mass timber helped kickstart interest in the US. (Side note: Katerra recently acquired Michael Green Architecture.)

Nonetheless, the growing enthusiasm of builders and advocates seems to be chipping away at the resistance. Why are they so geared up?

The advantages of mass timber
1. It performs well in fire
Especially in the US, people associate wood in buildings with stick-frame construction, 2X4s and plywood, which are flammable AF. It doesn't help that the media has recently been full of images of stick-frame houses and subdivisions burning in California. It is everyone's first question about mass timber: what about fire?

The thing is, large, solid, compressed masses of wood are actually quite difficult to ignite. (Hold a match up to a large log some time.) In the case of fire, the outer layer of mass timber will tend to char in a predictable way that effectively self-extinguishes and shields the interior, allowing it to retain structural integrity for several hours in even intense fire.

Reports on fire testing of CLT come from the US Forest Service, the International Code Council, and the Fire Protection Research Foundation. (The Forest Service has also done extensive blast testing of CLT, which it passed with flying colors, opening the door to its use in military facilities.) The bottom line is that all building materials have to meet code, and CLT meets code for fire safety.

An interesting aside: Most people don't realize that "steel is terrible in fire," says Green. "Once it reaches a yielding temperature, it becomes highly unpredictable, and it's done. Your building has to be torn down." When Green does use steel, he often surrounds it with CLT to protect it in the event of fire.
2. It reduces carbon emissions
Roughly 11 percent of global greenhouse gas emissions come from building materials and construction; another 28 percent comes from building operations, which mostly involve energy. As energy gets cleaner in coming years, materials and construction will represent a growing fraction of buildings' carbon impact. That's what mass timber aims to reduce.

Determining the full lifecycle impact of mass timber on carbon emissions is a tricky business. At least three carbon effects must be tallied up.

First, some greenhouse gas emissions are released by the supply chain, starting with forestry. In logging, soil carbon is disturbed and released, plant and wood waste is generated that eventually rots and releases carbon, and emissions are generated by the vehicles and machinery necessary to cut the wood, transport it to the mill, and treat it. Notably, most conventional lifecycle analysis counts wood supply as carbon-neutral, assuming it comes from sustainably managed forests; as we will see later, that's not always a safe assumption.

Second, there is some amount of carbon embedded in the timber itself, where it is sequestered in buildings that could last anywhere from 50 to hundreds of years. Though the exact amount will depend on tree species, forestry practices, transportation costs, and a number of other factors, Green says a good rule of thumb (confirmed by this study) is that one cubic meter of CLT wood sequesters roughly one tonne (1.1 US tons) of CO2.

(Again, as we'll see later, this depends on some assumptions about forestry.)

Third and most significantly, substituting mass timber for concrete and steel avoids the carbon embedded in those materials, which is substantial. Cement and concrete manufacture are responsible for around 8 percent of global GHG emissions, more than any country save the US and China. The global iron and steel industry is responsible for another 5 percent. Something like half a ton of CO2 is emitted to manufacture a ton of concrete; 2 tons of CO2 are emitted in the manufacture of a ton of steel. All those embodied emissions are avoided when CLT is substituted.

Exactly how those three carbon effects balance out will depend on individual cases, but research suggests that, for all but the most poorly managed forests, the overall impact of using CLT in place of concrete and steel will be a reduction in GHGs. A 2014 study in the Journal of Sustainable Forestry looked deep into the question of the carbon effects of large-scale substitution of wood products for alternatives and concluded: "Globally, both enough extra wood can be harvested sustainably and enough infrastructure of buildings and bridges needs to be built to reduce annual CO2 emissions by 14 to 31% and FF consumption by 12 to 19% if part of this infrastructure were made of wood." The biggest drop in CO2 emissions came, it said, from "avoiding the excess [fossil fuel] energy used to make steel and concrete structures."

More recently, a team at the University of Washington attempted a full, soup-to-nuts lifecycle analysis comparing a "hybrid, mid-rise, cross-laminated timber (CLT) commercial building" to "a reinforced concrete building with similar functional characteristics." After tallying up all the many factors, they concluded that the CLT building represented a "26.5% reduction in global warming potential."

That's likely a decent rule-of-thumb estimate, though again, that number could be pushed in either direction by better or worse forestry, transportation, milling, construction, and disposal practices.
3. It allows buildings to be constructed faster, with lower labor costs and less waste
Rather than materials being ordered in mass quantities, cut to size on site, and assembled, as with conventional construction, much of the labor and fabrication for CLT buildings is done at the factory, often using "computer numerical control" (CNC) machines to allow precision cuts.

If provided detailed plans by architects and designers, the factory can fabricate, e.g., a CLT wall exactly to specifications, with door and window openings in the right places and space for plumbing and electric. It virtually eliminates material waste - there are no door and window cutouts to throw away because the wood was never put there in the first place. With computer-guided fabrication, wood is placed only where it is needed.

Because these prefabricated pieces can be assembled a few at a time, in sequence, with relatively little labor, they can be shipped to the construction site on a just-in-time basis, avoiding massive on-site inventory and minimizing on-site disruption. Construction projects can be squeezed into tight, idiosyncratic urban spaces.

Even tall towers can be constructed within weeks, with low labor costs. According to the softwood lumber industry, "Mass timber buildings are roughly 25% faster to construct than concrete buildings and require 90% less construction traffic."

Factory-based manufacturing "will create a high level of repetition that will blow out the waste and wasted costs" of conventional building, Green says, eventually making something like a kit of parts for house incredibly cheap.

Indeed, in a story for National Geographic, journalist Saul Elbein writes about John Klein, an architect at MIT, who believes "his firm could offer the teeming cities of the 2020s a line of standardized, customizable, mid-rise apartments and office buildings, largely made of modular mass timber, that developers could order to spec like IKEA sofas."

Right now, Klein says, "every building is a prototype," designed and built once. Mass timber will help change that.
4. It is fantastic in earthquakes
The performance of mass timber in earthquakes has been much tested (and tested and tested) and has proven remarkably good.

While concrete simply cracks in earthquakes, which means concrete buildings must be demolished and replaced, wood buildings can be repaired after earthquakes.

Mass timber is also lighter and can be built on urban land, e.g. brownfields, not suitable for heavy concrete construction.
5. It is aesthetically and even spiritually appealing
Wood is often left exposed in mass timber buildings - it doesn't need to be wrapped or bolstered to meet code - and there is nothing quite so beautiful as large expanses of exposed wood. It is appealing on a primal level, a connection to nature. Wood is "nature's fingerprint in buildings," as Green puts it, and it has a deeply soothing effect.

Architect Susan Jones of Atelierjones LLC oversaw the building of one of the first CLT single-family residences - her home of five years in Seattle, built to super-efficient passivhaus standards. ( It was featured in Dwell Magazine.) "We love living there," she says. The interior is entirely swathed in timber and "the acoustics are incredibly rich, there's a beautiful tone, you can still smell a little bit of pine scent in the air, and the way it captures the light is absolute magical." Jones says, all things considered, building her home with CLT added about 8 percent to total costs.

(See also this very cool CLT home in Atlanta, which you can rent via Airbnb.)

Mass timber is also a good natural insulator: "Softwood in general has about one-third the thermal insulating ability of a comparable thickness of fiberglass batt insulation, but about 10 times that of concrete and masonry, and 400 times that of solid steel." That makes it particularly good for windows and doors.
6. It can help pay for good forest management on public land
Forests in the West have become tinderboxes, in part thanks to climate change and in part thanks to years of poor management. They are filled with trees dead or weakened from pine beetle infestations. Decades of overzealous fire protection have left them choked with closely clustered, small-diameter trees. Lately, with all this kindling around, "there's so much fuel, the intensity of the fire wipes out everything," says Hilary Franz, commissioner of public lands in Washington state. The land is being permanently scarred.

The forests on public lands badly need thinning, but there's never enough funding. This has given Franz an idea: use weak and small trees, for which there is no other market, for mass timber. (Logs with tops as small as 4.5 inches will work.)A sufficiently large market for mass timber would create funding for thinning those trees out. As a bonus, Franz wants to use mass timber to build low-cost affordable housing on publicly managed land.
7. It can create jobs in struggling rural areas
Softwood (mostly pine, spruce, or fir) forests in the US are predominantly found in the Northwest and the Southeast, and the communities that live and work in them have been struggling, especially since the housing crash and the great recession.

New demand for softwood could help reopen some of the closed mills and revive some of those communities, aligning their interests with a Green New Deal-style program of national revitalization.
8. There is no other choice
In his TED talk, Green notes that billions of people worldwide lack homes - a half-million in North America - and will need to be housed in the coming century, largely in cities. If all that urban housing is accomplished with concrete and steel, the climate is hosed.

"Over the next 20 years, more than half of new buildings expected to 2060 will be constructed," reports the United Nations Environment Program (UNEP). "More alarmingly, two-thirds of those additions are expected to occur in countries that do not currently have mandatory building energy codes in place."

A more sustainable alternative must be found. And wood is the only material sufficiently abundant and renewable to do the job. We've got to figure out how to make it work. "We have no choice," Green told me. "This is the only option."

Reservations about mass timber

In all that I've read and among everyone I've talked to about mass timber, I have encountered nothing but enthusiasm about its architectural properties. The one exception may be the Build With Strength coalition, which fought mass timber's inclusion in the IBC, characterizing it as rickety, highly flammable, and environmentally unsustainable. But Build With Strength is, ahem, sponsored by the concrete industry.

By and large, architects and builders are excited about mass timber, as are timber businesses and communities, timber-state politicians, climate hawks concerned about the carbon impact of building, and city officials looking for ways to accelerate decarbonization (and win some good PR).

It hasn't all been smooth sailing - several CLT panels cracked and collapsed during construction of an Oregon State University building in March 2018; plans for a wooden tower in Portland, Oregon, fell through - but the tailwinds behind mass timber are strong. A material that can be grown in abundance, creates rural jobs, reduces construction waste and labor costs, and slows the growth of concrete and steel seems like a win-win-win.

The good-faith reservations that do exist are about the supply chain, and they come in two forms.

First, protecting and properly managing forests is a huge part of fighting climate change and preserving a livable world. Intact forest ecosystems provide not only carbon sequestration but ecosystem services, wild animal habitat, recreation, and beauty.

Environmentalists worry that North American forests are not sufficiently protected to weather a sharp uptick in demand. The Natural Resources Defense Council has a harrowing report on the (systematically undercounted) amount of GHGs being released by clearcutting in Canada's boreal forest, as intact ecosystems are replaced by managed forest monocrops. (More on the damage to the boreal in this report.) Oregon Wild has a similar account of that state's outdated forestry rules, some of the weakest in the nation.

There are two competing certification standards for harvested wood: the Sustainable Forestry Initiative (SFI), sponsored by the industry, and the Forest Stewardship Council (FSC), an independent body created by environmentalists. Unsurprisingly, the FSC standards are considerably more strict regarding clearcutting, pesticide use, and more. Though the SFI has its defenders and has made reforms recently, environmentalists remain unimpressed and several architects and builders I talked to strongly preferred to source FSC wood. (Jones said she suggests it to clients, but it adds a 10 percent premium, so they don't always go for it.)

Second and relatedly, some environmentalists worry that the sequestration benefits of wood as a building material are being overestimated.

The International Institute for Sustainable Development issued a report last year looking at gaps and weaknesses in lifecycle analysis as applied to building materials, wood in particular. They found that "existing LCAs produce widely variable results, even for similar buildings," that there is wide regional variability in building performance, and, most notably, that LCA tends to exaggerate the importance of "embodied carbon" in the wood by ignoring or underplaying emissions in other parts of the life cycle.

Specifically, it said, the most uncertain parts of most LCAs have to do with carbon sequestered in woodand carbon released at the end of life - two issues of central importance to mass timber.

Numerous environmental groups, led by the Sierra Club, signed an open letter to California state officials in 2018, urging caution about mass timber. Notably, they did not oppose it outright. They argued that, thanks to current forestry practices, its climate benefits have been exaggerated. "CLT cannot be climate-smart unless it comes from climate-smart forestry," they said.

The letter provides a short list of principles that should guide climate-smart forestry, including: "Logging of the world's remaining mature and primary forests, as well as unroaded/undeveloped and other intact forest landscapes, should cease." And: "Tree plantations should not be established at the expense of natural forests."

While it is not perfect, they concluded, "FSC certification of privately owned forestlands can support progress in the right direction."

"There's no question that [FSC] is the gold standard," says Jones, "but it's all better than not doing anything."

Mass timber must be coupled with sustainable forestry

What should we conclude from all this?

There are many ways to reduce the environmental and climate impact of the building sector, some of which are arguably more important, at least for now, than the embodied carbon of materials. They include dense urban infill and multimodal transportation, more sustainable supply chains and construction practices, electrification of heating and cooling, and better building performance (efficient heat, light, and air circulation).

But still, the math is clear: It will be a disaster if we try to accommodate a rising, urbanizing 21st century population with buildings made of concrete and steel, just as it will be a disaster if we try to do it with energy generated from fossil fuels.

Mass timber appears to be the only viable alternative. And it's cool! It cuts down on waste and costs, opens up the possibility of factory-based mass production of low-cost housing, and has sparked the interest and creativity of the building community. "It's so much fun!" Jones says.

As cool as it is, though, it would also be a disaster if a turn to mass timber resulted in further loss of mature forests and intensified clearcutting. The impact of unsustainable forestry could undo the rest of the benefits.

To me, the moral, economic, and strategic arguments all point in the same direction: Mass timber is worth celebrating and supporting, but it must always and everywhere go hand-in-hand with a renewed emphasis on climate-smart forestry. At the very least, everyone advocating for or involved in mass timber should be pushing for FSC certification standards to become a regulatory floor, not a voluntary ceiling.

There is enough wood; Green estimates that it takes about 13 minutes for 20 North American forests to collectively grow enough wood for a 20-story building. But if we want the forests to do more for us, to provide all our apartments, offices, and houses, we must care for them so that they can do the same for future generations.

Further reading

Some detailed resources for people who want to get into mass timber:

The industry group Think Wood has a CLT Handbook, which covers "manufacturing, structural design, connections, fire and environmental performance, and the lifting and handling of CLT elements." It also offers numerous pages on specific mass-timer topics like CLT.

The structural engineering design firm Fast+Epp has a Developer's Guide to mass timber, a "brief overview of different types of mass timber, examples of recent mass timber towers, marketing opportunities, and construction advantages and risks."

Canadian Architect magazine has an extremely detailed primer on mass timber from the perspective of structural engineering.

Central City Association of Los Angeles has a nice white paper summarizing mass timer.

Utility Dive has an interview with architect Andrew Tsay Jacobs that it bills as "mass timber 101."

A few well-done, accessible popular-media introductions to mass timber:

And don't miss Michael Green's TED Talk.

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The hottest new thing in sustainable building is, uh, wood

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Architects, builders, and sustainability advocates are all abuzz over a new building material they say could substantially reduce greenhouse gas (GHG) emissions in the building sector, slash the waste, pollution, and costs associated with construction, and create a more physically, psychologically, and aesthetically healthy built environment. The material is known as, uh, wood.

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When fire is applied to wood boards, the burning process creates a thin layer of carbon on the wood surface, which is what we see as burnt wood. This carbon layer protects the interior wood in very much the same way that stains or sealants would.

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How is wood used?

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Using fire to burn patterns/designs or shapes into wood

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Using fire to burn patterns/designs or shapes into wood

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Wood burning releases carbon dioxide, also warms you not globe

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Physically
Psychologically/Emotionally

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How does wood interact or play a certain role in the environment? With other living things?