Gambrel Roof Rafter Layout

Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth.

Gambrel roof rafter layout. How to build perfect barn style gambrel roof trusses. Either use our standard design or we can custom build to your design. Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape. This approach conforms to my general design philosophy when in comes to the structural design of houses.

Volume of building equal to gothic type building. Build the trusses now because the empty floor will be part of your temporary truss jig. A regular gambrel fits inside a circumscribed semi circle and is essentially one half of a regular octagon. The numbers vary depending on your local design wind speed zone but the bottom line is that you can use the same hardware here that you would use if the roof were an ordinary 12 pitch roof with straight rafters.

Place a 6 in 12 in 15 cm 30 cm rectangular piece of osb or 3 4 in 1 9 cm thick plywood under the joint of an assembled rafter. Then use a saw to cut the lines that you drew. Purlins joints are used slopes are fixed and the length of the top and bottom rafters including overhang will always be equal. Trace and cut osb or plywood joints to connect the rafter pieces.

Trace the top of the joint so the angle is at the same degrees as where the rafters connect. Click here to see more shed building videos. Design is flexible enough to fit your own design needs.