Craftsmanship Series: The Use of Wood in Architecture and Design, Part I
As part of our Craftsmanship in Architecture Series, we will be discussing the use of wood in architecture and design. This topic will span several posts, with this first one focusing on wood sources, sustainable considerations, and species selection criteria. Wood is a nearly perfect building material. A renewable resource, it is readily available and easily harvested in most areas. Wood is excellent structurally, in both tension and compression, and can be easily machined, shaped, and otherwise fabricated for finishes, furniture, and decorative uses. Many structures, ranging from Buddhist temples to traditional houses, are made almost entirely of wood. Even structures predominantly constructed of stone, concrete, glass or steel, rely on wood for forming, blocking, or other temporary uses. It is nearly impossible to imagine a building process devoid of wood.
Sustainable Wood Sources
Forest covers about 30% of the earth’s land, but is shrinking rapidly in some areas as land is cleared for farming and development, or wood is cut for sale. The Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forrest Certification (PEFC) are two major programs aimed at protecting forest land from over harvestation. Both use some form of chain-of-custody certification which traces the path of products from forests through the supply chain. In the US, major suppliers of wood products are now practicing sustainable harvest techniques and strive to plant more acreage than they cut. Two major US based suppliers of lumber and wood based products, Georgia Pacific and Weyerhaeuser, both have strong commitments to sustainable forestry practices. In Canada, the Boreal Forest Conservation Initiative is just one of the many groups working to maintain the health of the vast Boreal Forest regions.
Recycling and reuse of wood has become much more popular in recent years. Salvaged lumber can often command higher prices than new lumber; prized for its first growth density and lack of defects. Heart pine flooring is sawn from dismantled structural timbers or from logs sunk for decades on river bottoms. The rich color is unmatched by wood cut today.
Technology is also allowing better utilization of wood by eliminating almost all waste. Engineered wood products, includinged laminated beams, panels made from scraps and sawdust, and flooring formed with just a thin layer of valuable wood coupled with layers of less precious species, are readily available in the market Not only does this promote sustainability, it also makes the wood products stronger and more stable.
Choosing Appropriate Wood Species
There are hundreds of different species of wood native to regions spread across the globe, from Spruce in Finland to Rosewood in Brazil. Some species resist decay well and work best for exterior applications, while others are easy to work and finish; lending themselves more toward interior uses. Cost and availability are also a big consideration in selecting wood for a project. A few examples: Fir, Pine, and Spruce, from North America (and other places) are very versatile, while they are often used for structural members, they are also used for siding, flooring, and other interior finishes. Most of these are readily available in North America and costs range from low to moderate depending on quality.
Oak, Cherry, Maple, and Walnut are examples of classic North American hardwoods and are often used for decorative interior finishes and fine furniture. Natural colors range from a light blond to a dark rich brown depending on the species. Availability is generally good and costs span a wide range.
Mahogany, from either South America or Africa, is very stable, easy to work, and also resists decay. It is often used for high end doors and windows, but is equally popular for interior paneling and furniture. Mahogany is general easy to get and prices tend to be moderate.
Cedar is light in weight, resists decay, and is often used for roof and wall shingles on residential construction. It is readily available and cost is not particularly high.
Ipe, from Brazil, is extremely hard, dense, and decay resistant. It is often used for decks, railings and other exterior, high traffic applications. Its cost is relatively high and availability is uneven.
Exotics, such as Rosewood, Ebony, Makore, and a host of others are best suited for furniture, paneling, and decorative uses. These woods are not always easy to find and tend to be the most expensive.
In the next installment of Wood in Architecture and Design we will discuss how wood is cut, graded, and sold for use in the building industry. We will look at appropriate uses and detailing for solid lumber, veneers and engineered products, and how to properly finish and care for wood.
The preceding was authored by DMSAS Associate Ted Houseknecht. Ted received his Master of Architecture from Arizona State University in 1988 and has been with the firm since 1991.