Typical Flat Roof Build Up

Also known as low slope roofs flat roofs are less common in north american residential construction because the low slope of a flat roof has an increased tendency to collect water rather than shed like its more steeply pitched alternative.

Typical flat roof build up. Tar and gravel 2. The recognised flat roof build ups for best design practices are. In the case of a flat roof insulation is usually either a rigid board above the deck or a mineral glass wool quilt immediately above the underdrawn ceiling depending on the type of roof design and construction. Built up roofs are manufactured using built up layers of either tar saturated paper and liquid tar with gravel asphalt rolled asphalt or modified bitumen.

Many slope in several directions like squashed hip roofs toward scupper holes that connect to downspouts. On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases. This may make it less ideal for rainy or snowy climates. Built up roofing also called bur is the most common roofing material used on low slope roofs.

It is composed of alternating layers of reinforcing fabric and bitumen asphalt and is finished with a top layer of aggregate such as stone or gravel. As the roof is installed more and more layers are added to increase durability and longevity hence the name built up.