The construction industry in the United States has a gross output of more than 2 trillion dollars and its contribution to the gross domestic product is more than 4 percent. Data from the U.S. Census Bureau also indicate that the specific residential construction segment accounts for more than 45 percent of the total construction spending. Hence, considering the scale of residential construction activities, the health of the entire construction industry also determines the demand for timber. The United States favors timber over concrete for most of its residential construction.
Why Wood Instead of Concrete: Explaining the Dominance of Timber in American Construction
Background on Timber Use in the United States
A combination of historical, economic, environmental, and cultural factors have influenced the use of timber in U.S. construction. This is the prime construction material used in building residential homes. In addition, due to advancements in engineered wood products, timber is increasingly utilized as a building component in various segments of the construction industry. These include commercial buildings and public infrastructure like bridges.
Several larger construction undertakings have also demonstrated the use of timber as one of the main building components. Examples include the 25-story building Ascent MKE Building in Milwaukee, Wisconsin which incorporated timber components alongside steel and concrete, and the 280-feet Placer River Pedestrian Bridge in Alaska which features glulam trusses and showcases the capability and feasibility of timber in large-scale infrastructure.
The U.S. produces over 30 billion board feet of lumber each year. However, despite its significant domestic production, it still needs to import lumber and timber to meet its consumption needs since the domestic capacity cannot meet existing and expanding demand. Canada, with its vast forest resources, remains the primary importer of wood products in the U.S. The second-term Trump administration has taken actions to boost domestic timber production.
Practical Reasons for Using Timber Over Concrete
There are two practical reasons why construction in the United States, especially its residential construction segment, favors using timber over concrete as its main building material. These are the immediate abundance of timber resources and the cost-effectiveness and ease of construction this material provides. Both represent the economic factors that have resulted in most construction undertakings defaulting to wood rather than concrete and steel.
North America has vast forested areas. For example, in the U.S. alone, the Pacific Northwest, parts of the Midwest, and Southeast provide an abundant and renewable source of wood. The Trump administration has also rolled out executive orders that would allow the use of trees in national forests and other public lands under the control of the federal government. Adding to this is the fact that the proximity of Canada makes importation cost-effective.
Wood is also cheaper and more accessible than concrete in the U.S. It is easier to transport and requires less specialized labor compared to concrete and cement construction since skilled workers are trained to use timber. Houses framed in wood are quicker to build. The same is true for houses that use prefabricated and modular components. This makes timber ideal for fast and large-scale housing development in areas that prioritize speed and efficiency.
The varied environmental conditions in the U.S. also favor using wood. For example, in areas prone to earthquakes, such as California, wood-frame structures perform better than rigid concrete buildings due to their flexibility and lighter weight. The natural insulating properties of wood also reduce heating and cooling costs. It is worth mentioning that it is about 400 times better than steel and 10 times better than concrete in terms of thermal resistance.
Specific Cultural and Regulatory Underpinnings
The abundance of timber led early settlers to adopt wood-frame construction. It was also a critical resource for the westward expansion during the 19th century. Timber was the main material used in building settlements, infrastructure, and transportation networks. It was also one of the main bases of the industrial revolution during the late 18th and 19th centuries. Demand for timber increased further during the housing boom after the Second World War.
Hence, considering the historical underpinning of wood-based construction, the preference has persisted due to availability. Americans have developed their aesthetic preference around the use of wood. It possesses a natural warmth and beauty that resonates with many Americans. Most American families also prefer single-family homes in suburban residential areas. This favors wood construction over multi-floor and dense concrete buildings.
Take note that building codes evolved around wood. These codes provide standards for structural integrity, fire safety, and energy efficiency specifically tailored to wood. Both inspection and zoning laws are also designed with wood construction in mind. Using materials like concrete or steel in residential homes often requires special permits and adherence to commercial building codes. These legal considerations underpin the preference for timber.
Even specific construction techniques were developed based on wood-based construction. Take balloon framing as an example. This involves using long vertical studs running from the foundation to the roof. Platform framing is the modern standard for residential house construction and it involves constructing floors and walls in sections. This technique is suited for assembling wood frames and incorporating pre-fabricated wood components in the design.
Exceptions that Favor Concrete and Steel Over Wood
It is true that timber has been used in building some larger structures. However, for large buildings and infrastructures, concrete and steel are the default options for strength and fire resistance. Concrete excels in compressive strength. Typical concrete used in construction has compressive strengths ranging between 17 MPa or 2500 psi and 28 MPa or 4 000 psi. This can go much higher. High-performance concrete can exceed 70 MPa or 10.000 psi.
Moreover, because concrete is weak in tension, it is reinforced with steel to create reinforced concrete. The resulting structure can withstand both compression and tension. Steel has an ultimate strength of about 400 to 500 MPa. Wood has a high strength-to-weight ratio that is 20 percent higher than structural steel and four to five times higher than non-reinforced concrete in compression. Reinforced concrete is the most favored for strength.
Areas prone to hurricanes like Florida and wildfires like California are seeing a growing trend of using concrete and cement-based materials for residential construction. Houses with reinforced concrete walls, insulated concrete blocks, and concrete blocks provide greater durability against Category 4 and 5 hurricanes. Building codes across different states are also evolving to favor and require the use of better materials based on environmental conditions.