Metal buildings are being used for more and more applications
Metal building systems manufacturers revolutionized building construction by providing single-source control for all parts of the building envelope beginning at the start of World War II. Metal building systems are used in a wide variety of applications, such as manufacturing plants, industrial and commercial warehouses, shopping centers and retail stores, auto dealerships, educational, transportation and health care facilities, office structures, hangars, churches, community centers, and governmental and recreational buildings.
One of the advantages of a metal building system, and one of the key reasons it is perhaps the best value in construction today, is the industry’s ability to utilize welded up frames as opposed to mill sections. In this way, the engineer uses sophisticated computer programs to design the most efficient shape for a frame. The industry puts the steel material where it is needed and eliminates it where it is not, thus effecting economy without compromising design. And, welded shapes are only welded on one side. There is technically no reason for welding on both sides unless shear force requires it, and shear force in rigid frames is usually relatively low.
The entire building system consists of an integrated set of components and assemblies, including, but not limited to, frames that are structural steel members, secondary members that are made with cold-formed steel and steel joists, and roof and wall cladding components systems specifically designed to support and transfer loads and provide a complete or partial building shell. Metal building systems can span great widths and lengths with or without additional interior supports. Where very large areas are required, and interior columns are not a problem, the modular rigid frame is an ideal solution. With a roof slope of 1/4 inches to 12 inches, even a 1,000-foot building can be designed without excessive height.
The roof secondary structural or purlin normally uses the lap method for economy and ease of installation. Lapping over the frame allows the purlins to act as a continuous beam with attendant efficiency and greatly reduces deflections compared to simple span purlins. Bay spacing up to 33 feet is possible when using purlins. The open web joists allow designers to specify bay sizes up to 60 feet and even longer.
Metal Roof Systems
Metal roofs are the other major component of metal buildings. Metal roofs are cost efficient and versatile, and can be constructed on most building types. It is even possible to retrofit older, non-metal roofs with a metal roof. The roofs can be standing seam (where the panels overlap and are attached by a concealed fastener system to the purlins below) or they can be through-fastened. A through-fastened roof is often a good, economical choice for smaller projects. With steeper pitched roofs, the color and look will be more important and must often conform to local standards and codes. The metal building system manufacturer can offer a wide variety of options in coatings and colors. For low-slope buildings, Galvalume material coated with a mixture of zinc and aluminum is primarily used.
For warehouse and distribution facilities, which are common and traditional uses for metal buildings, metal wall systems offer a wide range of profiles, coatings and colors. Insulating the building with fiberglass or insulated panels enables the building to achieve considerable energy efficiency, thus lowering energy cost and consumption.
Concrete, masonry and tilt walls are often used for metal buildings. Tilt walls can incorporate sandwich walls, where two walls are combined with an insulating layer in between to increase insulation. Masonry and concrete walls are often designed with exterior treatments that coordinate into a neighborhood, business park or community.
Windows, walk doors, overhead doors and a variety of other accessories can go just about anywhere and help facilitate the occupancy need. For retail and commercial facilities, storefront glass systems are commonly used for merchandising practices. Even load-bearing concrete tilt walls can be constructed with windows, so you can get natural light inside the building.
Perhaps one of the most proactive endeavors of the Metal Building Manufacturers Association (MBMA) has been the establishment of a quality assurance program for its members. MBMA’s board of directors has, over the years, repeatedly reaffirmed its commitment to a comprehensive quality assurance program that adds value for the end customer and differentiates the metal building systems industry from other forms of construction.
Wes Brooker is marketing manager at Nucor Fabricated Products, Charlotte, N.C. To learn more, visit www.nucor.com.