Metal roof systems have become a common choice for steep-slope roof applications. Standing seam metal systems are often applied on structures that had typically used shingle applications. The aesthetic value of metal roof systems is making them more in vogue with the architectural community and their use is increasing with schools, shopping plazas, churches and municipal buildings. In addition to great aesthetics, a standing seam metal roof system — when properly applied — can provide long term waterproofing protection. Successful metal systems require proper attachment procedures, provisions for expansion and contraction, and expedient removal of water (snow and ice) from the roof surface.
Metal roof systems are comprised of the metal panel, which is typically fabricated from 22 or 24 gauge galvanized metal or aluminum, and a batten fill insulation. The metal panels are anchored to the structural components with fasteners or clips. Roof clips are secured to pre-punched holes in the supporting structure. This is advantageous because it ensures proper alignment of the panels and allows for movement of the panels without causing damage to the roof system. For effective installation, the panels should be maximum length to minimize the number of end laps. The panel end laps should overlap the adjoining panel by a minimum of 6 inches and shall be adjoined together with a reinforcing plate, top panel strap and the proper manufacturer-approved sealant. The panels are typically not secured to the structure at these points to allow for panel movement. The seams are interlocked and should provide accommodations for movement in either direction for expansion and contraction. The batten fill insulation is applied at the underside or interior side of the panels and is attached directly to the panels. Some manufacturers offer composite panels that sandwich insulation between two factory-fabricated panels.