Low Slope Roof Construction Details

Roof penetrations should be kept to a minimum and should be located within the flat of the panel where possible as opposed to near seams.

Low slope roof construction details.

If the upper edge of a low slope shed roof intersects a vertical wall the most logical approach in my opinion is to detail the roof as an unvented roof. Generic valley treatment details for metal panel roofs for low slope with and without substrates are included in the mbma metal roofing systems design manual chapter 12 metal roof details. The roof assembly is defined as the roof deck along with the roof membrane and roof insulation. Problems at these points typically arise from improper application methods and the use of inappropriate or incompatible materials.

That includes soldered metal roofing or synthetic membranes. The roof system is defined as the roof membrane including surfacing and the roof insulation. The most critical application points on low slope roof systems are at flashings penetrations and accessories. Low slope roofs are often referred to as flat roofs.

By low slope roofing we mean any roof that is pitched at less than 4 inches of rise in 12 inches of run or 4 12 pitch. Regular asphalt shingles and standard skylights will work at pitches of 4 12 or greater but at lower pitches you have to use different materials. These critical junctures account for the majority of roof leaks. Roof assemblies with a pitch slope of less than 3 12 are considered low slope roofs.