Gable Roof Truss Design

The top chord smoothly extends out past the wall to create the overhang.

Gable roof truss design. Squaring building lines example use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters. Gable roof framing calculator plan diagram with full dimensions. This is used for gable roofs. A gable truss sits on the end wall of a structure and has vertical studs every 2 feet or 16 inches.

For a good straight fascia add an extra inch or 2 to the tails of all your rafters total length. Finally there is a barn type or gambrel shed roof. Wood roof trusses bring the bottom chord of the truss all the way to the outside of the wall include a small vertical cut butt cut and angles back against the top chord of the truss. Gable trusses are more expensive than common structural trusses because more lumber is required.

The truss sides will be equal in length and width to fit equally on the shed walls. If you re trying to reinforce a shed or gable roof use a simple king post truss design which has a single vertical joist running through the center of the triangular frame. They re often placed at the front and back of each other with the front pitch usually steeper. This is similar to the gable shed because the trusses will be in two different cuts because of the two different angles.

After they re up you can snap a line to mark and trim the tails in a nice straight line to make up for any ridge warp or marking cutting and fixing errors. The gable shed has a roof like a house so the roof trusses will have a peak in the middle. A gable truss isn t structural and needs a continuous bearing support underneath such as a beam or wall. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters.

Lay the first piece of siding on the truss assembly and allow 2 inches of overhang below the bottom of the simulated top plate.