Specifying Metal Roofs for Commercial Buildings

Specifying Metal Roofs for Commercial Buildings

When produced and installed appropriately, metal provides for a sturdy, long-lasting commercial roofing material. Elastomeric roof and single-ply roofs can outlive and outperform metal roofs. Despite the fact that they are costly an owner may overlook the initial cost considering the long-term interests. Metal roofs often last 30 to 40 years, but other systems only last 15 to 20 years.

Architects must consider a variety of aspects when specifying metal roofing, including the temperature zone of the site, the structure, roof pitch, form of the building, and local code requirements.

Choosing the Right Metal

Steel, copper, aluminum and zinc are the most frequent metals used for roofing. For increased durability, steel must be galvanized or coated, whereas aluminum is often painted or anodized. Zinc is preferred for its corrosion resistance whereas copper offers toughness, a proven long life, and a beautiful patina.

The thickness (or gauge) of the metal will influence the roofing cost. For durability, a lower gauge—and consequently higher thickness—is usually desired. Their larger weight, on the other hand, may make installation tough, and the higher thickness may make bending and working the metal more difficult.

Roof Connections and Configuration

Metal roofing comes in a variety of shapes and sizes, including vertical and horizontal sheets and panels, as well as shingles and tiles, which are most commonly used in commercial constructions. Different profiles can be used to connect metal panels, affecting the system’s longevity and maintenance requirements. Standing seam and batten seam roofing panels are all vertical possibilities. Standing seams are perpendicular to the roof plane and unite the edges of two neighboring panels in a single or double fold. Threaded fasteners and washers are used to mechanically attach the ribs. Wood strips at panel connections are flashed with a metal that interlocked with the panels in batten seam roofing.

Insulation and Underlayment

Synthetic sheets, asphalt-saturated felt, self-adhering are all options for underlayment. In hot weather, a slip sheet between the metal roofing and the underlayment may be required to keep the latter from sticking to the former.

Under the panels, a layer of insulation is essential for preventing thermal bridging and creating a sound fence in rain and hail. Extruded and expanded polystyrene, and fiberglass insulation panels are examples of rigid insulation boards for use over a solid deck substrate.

Standards and Codes

Architects should consult the applicable building code for their projects, as well as guidelines offered by professional industry associations and roofing manufacturers. See us for all required information on commercial roofing regarding panel connection, load bearing needs, ventilation, roof pitch, thermal insulation value at Tier 1 Contracting in OKC.