How To Lay Out Roof Rafters

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.

How to lay out roof rafters.

Place a 2 by 6 board on sawhorses to lay out the first full length or common rafter. Laying out and cutting rafters is one. After you determine the rise span run line length and pitch the next step is to lay out the rafters or mark the cuts on a pattern rafter to create the roof. 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.

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. Common rafters are the most common type of rafter in construction. Roof layout requires a number of steps. The ridge end of the rafter and often the eve end will need to be cut to the angle of the roof slope.

For every foot. 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. There are a number of methods to accomplish marking and cutting out rafters. 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.

Today we are tackling a big beginner lesson which is common rafter layout and cutting. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter. 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 roof on this shed is a 4 in 12 slope which makes it a 18 and.

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. I will attempt to describe the method i find that works the best for me.