Roof edges can be a major locus of failure in low-slope roofs. Our experts off er a dozen design tips to ensure that your covered – all the way to the edge. Faced with a constant barrage of wind and rain, roof edges are often the first line of defense for low-slope roof systems.

Roof edges also are the site of most roof failures, according to a study of 145 windstorm claims by Factory Mutual Insurance Co., Johnston, R.I., which found that 59% of roof failures could be attributed to perimeter failure.

Here are a dozen tips that will help your Building Team avoid edge-related roof failures, especially in high-wind areas.

1. Allow for thermal expansion and contraction. Since temperature change causes metal to expand or contract, the roof edge should incorporate slotted  fastener holes and snap-on covers that allow for thermal expansion and contraction, says Bob LeClare, a VP with W. P. Hickman Co., an Asheville, N.C.-based roof edge manufacturer. When building teams fail to plan for thermal movement, says LeClare, “You get some really ugly results.” One of the most common problems: “oil canning,” where flat metal sheets start to bend. Other problems caused by thermal expansion and contraction: split roof membranes, opening up at splices, and even disengagement and roof failure, says LeClare.

Read more ...