A beveled or triangular-shaped piece of lumber installed at the junction of a flat roof and a wall or parapet is commonly sourced from major home improvement retailers. It provides a gradual transition from the horizontal roof surface to the vertical wall, preventing sharp bends in the roofing membrane. This component is frequently used in low-slope or flat roofing systems to ensure proper drainage and waterproofing.
The strategic application of this material offers several advantages. It helps prevent ponding water at the roof-wall intersection, reducing the risk of leaks and water damage. This practice also extends the lifespan of the roofing membrane by minimizing stress and potential cracking caused by abrupt changes in angle. Historically, this construction detail has been recognized as a best practice for enhancing the durability and performance of flat and low-slope roofs.