Flat Roof Framing Terminology

Flat roofs are always built at a slight incline at least 1 8 inch per foot.

Flat roof framing terminology.

Flat roofs are hard to replace. A flat roof is a roof which is almost level in contrast to the many types of sloped roofs the slope of a roof is properly known as its pitch and flat roofs have up to approximately 10. Roof truss a frame designed to carry the loads of a roof and it s covering over the full span without intermediate support. Flat roofs are an ancient form mostly used in arid climates and allow the roof space to be used as a living space or a living roof flat roofs or low slope roofs are also commonly found on commercial.

They are common on extensions garages and commercial buildings. This article describes and illustrates the different types of support that prevents roof sagging and wall bulging at buildings including definitions of collar ties rafter ties and structural ridge beams. Some roofs actually slope in several directions ensuring optimal water runoff. Some observers suggest it s harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers especially on older flat roofs.

Line length is the hyptenuse of the triangle whose base equals the total run and whose altitude equals the total rise. Sarking is a strong moisture proof reflective metallic building paper which is placed over the roof battens purlins and installed beneath the external roof covering. This is to help prevent deflection and sag in the roof. If the unit of rise in inches is 3 then the cut is the unit of rise and the unit of run 12 inches or 3 12.

However green building uses a single top plate and ensures that rafters and ceiling joists sit on the plate directly over the studs. 1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches. When framing a flat roof you will need to create a slight incline. Figure 2 2 roof framing terms.

Top plate or plates in conventional western platform framing there are two top plates. Sway bracing there are a few ways to sway brace the wall. Collar ties rafter ties tension beams structural ridge beams. Some of these can support the roof and prevent ridge sagging and wall spreading.

The edge of a roof which runs from eaves to ridge at a gable. Here is a closer look at common roofing terms. Roof framing involves a lexicon all its own. 1 part of a pitched roof construction that receives the feet of the spars sp ars and ceiling joist ends.

Flat roofs are an often lower cost and easier to install alternative to traditional pitched roofs. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. 3 part of a suspended timber floor construction that provides a level bearing and. You can do this with a foam layer that exactly fits your roof.

As opposed to old built up felt roofing with joins new single ply waterproof membranes are now most commonly used. When repairing or replacing a roof it pays to be familiar with these terms. What is a flat roof. Includes illustrations that show roofs have hip rafters ridge boards jack rafters and more.