Over three billion pounds of aluminum are used annually in construction projects across the United States. Much of that total can be found in the aluminum roof and aluminum wall systems used on commercial buildings. The intrinsic properties of aluminum contribute greatly to its use in these metal building applications.
For example, aluminum is especially receptive to today's high-performance, architectural coatings. As a result, the wide variety of factory-applied coatings and colors perform well and stay colorfast. This is a crucial consideration in steep slope roof applications that make the roof a highly visible architectural element. The coatings also help ensure virtually maintenance-free performance and long service life.
Aluminum roofs also provide a high degree of radiant heat reflectivity regardless of whether it's low slope roofing or architectural steep slope roofing. This ability to deflect the sun's heat-generating rays results in less heat transfer to the interior of the building during the summer which, in turn, lowers energy costs by reducing cooling loads. Reflectivity is becoming increasing important as certain areas of the U.S. enact energy codes dealing with "cool metal roofing."
Because it is ductile, aluminum can be formed into a myriad of shapes and profiles. Its uses are by no means limited to flat metal roofing panels. Consequently, aluminum wall cladding systems can help create some of the most attractive and functional exteriors on buildings today. In addition, large wall panels, either flat or formed, require fewer joints, producing fast and economical installation.
And, aluminum wall systems are not meant for use only in new metal roofing construction. Retrofit metal roof applications are viable as well, especially when an owner wishes to change the "image" of a building. Aluminum wall panels, especially composite panels, are ideal for re-cladding older structures, as well as providing contemporary design options for all types of new buildings.
Aluminum is also corrosion-resistant. In fact, it is so corrosion-resistant that in most environments, aluminum requires no protective finishes. In highly corrosive environments such as marine applications, specially formulated aluminum alloys have been developed to enhance the anti-corrosive performance.
And, aluminum is light in weight. Buildings benefit from light but strong materials such as aluminum because less of the building's structure is expended in supporting its own weight. Buildings in seismically active zones benefit from reduced weight even more since seismic forces are proportional to the weight of the structure.
Aluminum construction products offer numerous environmental benefits as well. For example, a survey of aluminum producers in 2003 indicated that the total recycled content of domestically produced, flat rolled products for the construction market was approximately 80-85%. A subsequent survey indicated that on average; nearly half of the recycled content (40-42%) is from post-consumer sources.
Not only does the aluminum used in the construction industry contain a high percentage of post-consumer and post-industrial recycled content, but at the end of its long, useful life in a building application, it is 100% recyclable. In addition, aluminum building components can be repeatedly recycled back into similar products with no loss of quality. The recyclability and high recycled content of aluminum make it an ideal material for those looking for credits for the Leadership in Energy and Environmental Design (LEED) program.
The ability to recycle aluminum building products is also becoming more important as more building owners decide to deconstruct rather than demolish older buildings. Instead of simply going in with a wrecking ball, building owners are now much more deliberate about how they take down a building in order to extract as much recyclable building material as possible. By doing so, they not only retain the scrap value of a material such as aluminum but also eliminate the environmental impact and cost of dumping it in a landfill.
Aluminum recycling also reduces energy consumption. To produce aluminum from recycled material, for example, requires only 5% of the energy required to produce aluminum from bauxite. In addition, every ton of recycled aluminum saves four tons of bauxite.