How To Build A Cut Roof

And the line length measurement from the roof peak to the building wall is the hypotenuse.

How to build a cut roof.

The diagram above shows the components that go into making up a small gable roof. A horizontal cut called the seat cut and a vertical cut called a shoulder cut. The seat rests on top of the wall that you re attaching the particular rafter to while the shoulder cut parallels the wall and allows several inches of each rafter to overhang the roof. A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc.

The ceiling joists span from wall plate to wall plate and are sometimes bolted to the rafters to help stop the ridge. The rise or height of the roof at its peak is the altitude of the triangle. The run or half the building span is the base of the triangle. The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle.

If you re framing a gable roof on a new house or building a shed or even a doghouse with a gable roof you ll need to cut a number of roof rafters. A birdsmouth cut has 2 parts. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter. The ridge is a long board at the top that the rafters are nailed to.

Pitched roof construction. The roof rafters provide integral structural support to the roof.