Flat Roof Framing Basics

From there the flat roof system you choose will determine the materials you apply.

Flat roof framing basics.

A far more common method is to use firring strips which are battens cut at an angle and placed on top of the roof joists. Flat roofs are always built at a slight incline at least 1 8 inch per foot. Photo by russell kaye. Stick framing combines roof rafters with ceiling joists.

Partially these will depend on the style of roof you ve selected but you ll also have some wiggle room depending on the design elements of the house. When framing a flat roof you will need to create a slight incline. You can do this with a foam layer that exactly fits your roof. The framing style of the roof refers to the actual components of each roofing truss and the design of the structural foundation of that roof.

The run or half the building span is the base of the triangle. Most roofs utilize 16 inch spacings for strength and rigidity. Flat roofs operate with the same basic principle but of course their lower angles mean that gravity isn t quite as effective in shedding water rapidly. There must be some momentum for the water to move into the flat roof drainage system.

Mirrored pairs of rafters meet at a ridge and are connected across the base by a ceiling joist. Snap all layout lines on the floor before cutting any wall plates then cut every wall plate in the house before framing. Some roofs actually slope in several directions ensuring optimal water runoff. Like wall studs and floor joists rafters and trusses are spaced every 16 or 24 inches from center to center.

This will help you create a flat roof framing plan. Another possibility is to cut a fall into the roof insulation something several businesses now offer it s often referred to as tapered insulation. The rise or height of the roof at its peak is the altitude of the triangle. The rafters are usually positioned directly above the wall studs.

Tie all the intersecting walls together before starting to straighten and brace the walls. And the line length measurement from the roof peak to the building wall is the hypotenuse. The butt of a shingle is the end that faces down roof. The inherent strength and integrity of the triangular form makes the roof a sound structure.

A light rain or drizzle for example remain remain on a flat roof for a short period of time. The most important thing to know about a flat roof says tom is that it s not flat to prevent water from pooling and eventually invading the home flat roofs are always built on a slight incline at least 1 8 inch per foot. Collar tie also collar beam in profile the framing of a conventional pitched roof forms a triangle.