How To Lay Out Roof Rafters

Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.

How to lay out roof rafters.

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. For every foot. Laying out hip valley and jack rafters takes experience and skill but if you re building a simple gable or shed roof all you need is the common rafter the basic building block of roof framing. The first step in building the roof rafters is to cut one rafter board to length with the ends angled properly and then to mark and cut the birds mouth and seat on the rafter.

This article will discuss a gable roof without valleys or dormers because it s the most common and the easiest for a first time builder to tackle. Today we are tackling a big beginner lesson which is common rafter layout and cutting. To lay out a common rafter you need the pitch of the roof expressed in units of rise per foot of run in the gable roof example shown here a rafter with 6 in 12 pitch rises 6 in. Common rafters are the most common type of rafter in construction.

I will attempt to describe the method i find that works the best for me. Check the board for crown any slight curve in the length and designate the outside of the crown as the top side of the rafter. The pitch and span of your roof will dictate how long of a rafter you ll need use maximum span calculator to help you find your rafter size. Roof layout requires a number of steps.

The roof on this shed is a 4 in 12 slope which makes it a 18 and. Rafters should always be cut and installed with the crown up. If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Laying out and cutting rafters is one.

The roof rafters provide integral structural support to the roof. Place a 2 by 6 board on sawhorses to lay out the first full length or common rafter.