How Wooden Structures Can Help Improve Sustainability
Construction is one of the industries that is the most sensitive to swings in the economy, while at the same time being one of the costliest to modernize. However, entrepreneurs in this sector, along with governments and universities, have for several years sought to move toward more sustainable materials and processes that improve the image of the sector. Thus arose the idea of upgrading the value of wood and promoting its use as a structural material.
Upgrading the value of wood as a construction material
In this era of cement, glass, and steel, wooden structures might appear somewhat ordinary and not very durable. The reality is that wood has been used in construction for centuries, and many buildings made of wood have withstood the test of time. However, given the rise of the iron and steel industries, throughout most of the twentieth century, wood fell into disuse in construction or was used only for auxiliary purposes. Meanwhile, as a result of the uncontrolled deforestation caused by the expansion of agriculture, wood has become an expensive and scarce product.
But the twenty-first century brought with it the need for greater environmental awareness on the part of both governments and the private sector; in fact, the United Nations launched the Global Compact, an appeal that called on companies to add their efforts to the cause of environmental protection by developing new technologies that would provide basic solutions for replacing products made from non-renewable or fossil-based raw materials.
Thus, together with policies stimulating reforestation, there appeared ventures involving growing trees for timber and a new perception of the value of using wood in construction.
Wood, as a structural element, when compared with iron, steel or cement, has proved to have many advantages and qualities that have until recently seemed little known, even to professionals in the field. At the beginning of this decade the Spanish Confederation of timber entrepreneurs (CONFEMADERA) and the Instituto de Biomecánica de Valencia [Biomechanical Institute of Valencia] (IBV) created “Living with Wood”, a program dedicated to making known the benefits of using wood in various industries, such as construction and its related applications such as interior design, furniture, and framing; it also involved cooperation with new European regulations regarding the use of wood. We now know that wood, as a construction material:
- Is natural
- Stores CO2
- Does not generate toxic waste
- Is sustainable and renewable
- Is fire-resistant
- Acts as soundproofing
- Acts as a shock absorber
- Creates a feeling of comfort
Wood and global sustainability
Because of the spread of environmental problems caused by deforestation, such as desertification and flooding, the public has formed a negative image of the forest industry. It is true that if this industry does not take environmental factors into account the land and its ecology can be subject to drastic changes. However, as it is now, the forestry industry has succeeded in holding back the deforestation process; in fact, in industrialized countries, the size of forested areas is actually increasing.
If the various operations of the forest industry take all factors (environmental, ecological, social and cultural) into account, they have decidedly positive effects on the environment.
- Tree planting has many benefits, among them being: contributing to greater absorption and fixation of carbon, thus reducing the greenhouse effect; stabilizing slopes and controlling flooding; recovering degraded soils and protecting water resources; providing greater opportunities for leisure and recreation; increasing biodiversity; and reducing the need for logging in natural forests.
- Using natural forest and plantation resources allows the public to have more access to natural forests; it reduces the risk of diseases and forest fires, and fosters development without affecting natural forests;
- Cultivated forests are a strategic resource, generating economic activity, job opportunities, and exports.
Timber structures and sustainable buildings
Sustainability is a concept whose application is not limited to caring overall for the environment of the planet Earth, our common home; instead, it has expanded to embrace virtually all activities and industries.
Sustainability means acting in such a way that current resources can be used without compromising the possibility of their being used by future generations. Sustainability ensures the development and well-being of those who come after us, continuing the life cycle.
In the construction industry, these ideas have led to the concept of “sustainable construction.”
Sustainable construction…is not limited to an architectural style; instead it involves caring for the environment by:
- Efficient energy use
- Use of renewable energy sources
- Use of environmentally friendly building materials and products
- Implementation of integrated waste management
- Analysis of the environmental impact of the location of each construction project
This new concept is steadily gathering strength in the construction industry; and in these respects wood is revealed as the truly natural material of the twenty-first century, with applications in various aspects of the industry, from traditional enclosures to complex spatial structures, surpassing many of the standards met by concrete and steel:
- Because wood stores carbon dioxide for many years, it helps mitigate the greenhouse effect and prevent climate change.
- It takes less energy to produce lumber than other materials such as steel and aluminum.
- Its strength to weight ratio (bending strength) is 1.3 times that of steel, and 10 times that of concrete.
- It has high tensile and compressive strength.
- Its elasticity is low, half that of concrete, and twenty times less than steel.
- Its good response to fires: although components made of wood are flammable, solid wood is fire resistant. It does not burn quickly; to start burning, it requires surface temperatures exceeding 572° F over a period of time. In the event of a fire, wood is safer because its low thermal conductivity decreases the temperature toward the inside. The carbonized layer is six times more insulating than the wood itself, acting as a barrier to the release of gases and penetration of heat, thus slowing the advance of combustion. Its very low thermal expansion coefficient means that heat does not cause structural changes. In a fire, the weakest point of a wooden structure, the joints, can be strengthened by the use of metal.
- Shock absorption: wood’s shock-absorbing capacities are somewhat stronger than those of other materials.
- New products derived from wood, such as solid wood, laminates, and panels increase its uses.
- Creation of a feeling of comfort: the warmth and naturalness of wood influences the mood of those living in or visiting a home. Wood offers a sense of well-being, improving emotional states and lowering stress and the risk of illness.
Plywood is a product created by new technologies in the use of wood; thin layers of wood of uniform thickness are bonded lengthwise by means of grooves and gluing. It is used to make structures involving large spans, and it can solve complex geometric problems at competitive costs. In addition, quality standards for the production of laminates ensure that plywood is reliable and durable.
Another advantage of laminates is their lightness (10 times lighter than concrete and 3 times lighter than steel under the same structural demands). This allows buildings to be lighter, while reducing costs. Being prefabricated, plywood is ideal for dry construction. Sheets of plywood can quickly be put together, minimizing waste and the need for on-site infrastructure.
Fir (pieca abies), treated preventively with waterproofing, fungicides, and insecticides, is used for making laminates. The moisture content and thickness of each planed layer is controlled. Adhesives bond the layers, providing strength and durability, and ensuring that the integrity of the laminate is maintained throughout the useful life of the structure. The finish is created by high-quality planes that ensure even surfaces.
Plywood is an eco-friendly product with virtually the same qualities as solid wood; it is a renewable material, and the energy cost of transformation is very low in comparison with other materials such as steel, concrete, or aluminum. Its manufacturing waste can be recycled.
Plywood’s mechanical properties, versatility and response to fire mean that it can compete favorably against other construction materials such as concrete, steel or aluminum. It has high resistance to corrosion, so it can be widely used in activities carried out in aggressive environments, such as chemical plants, vessels for shipping livestock, and ocean-front buildings.