How To Lay Out Roof Rafters

Common rafters are the most common type of rafter in construction.

How to lay out roof rafters.

Laying out and cutting rafters is one. Today we are tackling a big beginner lesson which is common rafter layout and cutting. There are a number of methods to accomplish marking and cutting out rafters. The roof rafters provide integral structural support to 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. For every foot. 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. The roof on this shed is a 4 in 12 slope which makes it a 18 and.

If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Roof layout requires a number of steps. Rafters should always be cut and installed with the crown up. 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 end of the rafter and often the eve end will need to be cut to the angle of the roof slope. 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. 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. 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.

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. Place a 2 by 6 board on sawhorses to lay out the first full length or common rafter.