Shed Roof Rafter Design

Half building width minus 1 2 ridge thickness.

Shed roof rafter design.

Do you want to build a shed that makes a perfect garden shed. It is possible to calculate a birdsmouth near the top of the rafter for a freestanding shed roof by checking the kneewall checkbox and entering a setback for the kneewall that positions the upper birdsmouth in the desired location. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. A shed roof slopes in one direction only.

Let s consider a basic gable wood roof framing design. The roof on this shed is a 4 in 12 slope which makes it a 18 and one half degree angle on the board ends. So use your speed square and measure your angle. Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

Much depends on the structure size and the desired attic loft or headroom. You are going to cut out triangles that will cover the apex of each set of rafters. A simple gable shed roof is often built using 2 4 or 2 6 lumber for the rafters and 2 4 for the collar ties. See rafter run to outer wall calculator below.

So much so that it is my very favorite style shed for a garden shed. Continuing on from part 3. A rafter or speed square will have marks for both of these angles. A gable roof for a shed can be built with rafters with a 1 6 ridge board or using trusses.

The ridge end of the rafter and often the eve end will need to be cut to the angle of the roof slope. How to frame a gambrel shed roof. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. The rule of thumb is that the gusset should be twice the width of the wood you use for your rafters.

This will allow them to join and form the peak of the roof and let the other end fit nicely at the 60 degree angle of the bottom chord. Then cut the rafter angle at 30 degrees for two 2 4 s. For an 8 10 shed one sheet of plywood should be fine. Now you have extra 2 4 hanging over the bottom chord.

Here we have a wood framed gable roof. Measure your rafter boards for your preferred roof style and pitch. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. The rafters on a steeply sloped roof for instance will be much longer and have more end cuts than those on a flat roof.

The exact length and angle of your rafters will depend on the overall size of your shed as well as the style and slope you ve chosen. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. So roughly 7 8 long for a 2 4.