Gambrel Roof Plywood Gussets

Used a gambrel roof using plywood gussets used 3 4 so the two sides match the rafter thickness and did not cut them full triangles.

Gambrel roof plywood gussets.

The gusset system relies on a pair of 3 4 inch fir plywood gussets at each joint with the rafters sandwiched in the center. You must also use glue construction adh. With your first truss measuring out ok its time to cut and attach gusset plates. Gambrel roof framing geometry calculator inch this gambrel roof fits in a semicircle and starts as the top half of an equal sided octagon.

Raised custom gambrel only the raised joint supports the upper rafters on walls with the lower rafters butted against wall studs. Nail on gusset plates. Start with the top corners of the roof first. The gambrel spans 10 feet.

For the gambrel truss we will need 6 total gusset plates made out of 1 2 material like osb or plywood. Keep in mind that i used a ridge beam not a ridge board which substantially reduces the load and outward thrust issue. With that said when designing gambrel roof it s very important to consider wind load and other load factors because of the odd angled shape and not having ceiling collar ties you have increased chance for rafter movement under wl ll and dl so the gussets must be sized correctly if not your roof. Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape.

If plywood is used the rule of thumb is 3 4 to match the thickness of the sandwiched rafter. Plywood gussets could then be used to reinforce the joint if necessary. Place the osb or plywood on the top portion of the rafters and make sure that the edges run flush. Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth.

Nail along the edges of the osb or plywood driving the nails into the rafters every 8 inches 20 cm with 8d common nails. You might want to read through this thread as well gambrel roof. Nail osb or plywood onto the rafters to enclose the roof. Taken together the plywood pieces have the same thickness as the rafters themselves.

As long as the joint is adequately nailed the assembly acts as a single unit and is equivalent to a continuous sawn lumber rafter. Using this method it will take under an hour to cut all the 1x4 strips and gusset plates.