How To Cut Porch Roof Rafters

The roof rafters provide integral structural support to the roof.

How to cut porch roof rafters.

Plumb cut typically called the ridge cut at the top end of the rafter. A common rafter has three basic parts you need to become familiar with. This is the easy way to figure the angle to cut a porch roof rafter. The run is 96 x 12 65 length factor for a 4 12 roof 1214 4 divided by 12 101 2 inches.

Tail cut which may be cut plumb or square depending on how the eaves are detailed. To find the length of your rafters multiply the run in inches by the rafter length factor and divide by 12. Birdsmouth which consists of two cuts a horizontal seat cut and a vertical shoulder cut. Here s a simple formula to help figure out the angle cut at the top of a shed roof when it lies on the main roof.

Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter. When you cut the rafters you ll need to make 3 separate cuts. The ridge cut also called the plumb cut at the top of the rafter the birdsmouth cut which itself comprises 2 different cuts where the rafter meets the building s wall and the tail cut at the base of the rafter. Add the overhang space the same way.

Then force the rafter s tip snugly against the house wall. Http amzn to 2sfscbz swanson speed square http amzn to 2svgnvt 16 x 24 framing square starrett http amzn to 2sflm5v milwaukee circular saw http amzn. Usually it can be found on the plans when building a new home. First you must know the pitch of the main roof and the porch or shed roof.

To cut sloping rafters for a house attached patio roof lay a rafter board so it rests on its edge on both the ledger and the beam parallel to the ledger.