Shed Roof Rafter 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.

Shed roof rafter design.

However architects have recognized the potential of this form of design and now the shed roof is becoming a common feature among modern homes. See rafter run to outer wall calculator below. You are going to cut out triangles that will cover the apex of each set of rafters. Now you have extra 2 4 hanging over the bottom chord.

Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. 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. Measure your rafter boards for your preferred roof style and pitch. The ridge end of the rafter and often the eve end will need to be cut to the angle of the roof slope.

Much depends on the structure size and the desired attic loft or headroom. Then cut the rafter angle at 30 degrees for two 2 4 s. Easy rafters is designed to calculate shed roofs that are framed to a ledger board nailed against a vertical wall not freestanding shed roofs supported by walls at both ends. 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.

A shed roof slopes in one direction only. Half building width minus 1 2 ridge thickness. The rafters on a steeply sloped roof for instance will be much longer and have more end cuts than those on a flat roof. An alternative method of roof framing using purlins and roof trusses.

House with a shed roof an economical alternative to a traditional gabled roof ten years ago the shed roof was more common on actual garden sheds and garages not homes. Trussed rafters this method of gable shed roof design makes each set of rafters into a lightweight truss. By tying the rafters across at eaves level you stop the deadly eaves spread mentioned in method 1. 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.

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. 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. The rule of thumb is that the gusset should be twice the width of the wood you use for your rafters. So roughly 7 8 long for a 2 4.

For an 8 10 shed one sheet of plywood should be fine. 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. Allow for ridge thickness when determining rafter run to outer wall.