Roof Truss Thickness

This free online truss and roof calculator generates the axial forces and reactions of completely customisable 2d truss structures.

Roof truss thickness.

Sheathing should be a minimum of 19 32 inch thick. In general a roof truss manufactured from 2 by 4 lumber will support as much roof load as a 2 by 6 or 2 by 8 rafter. Roof sheathing standard roof sheathing which consists of 4 by 8 sheets of plywood or oriented strand board or osb is 1 2 inch thick and attaches directly to the roof rafters or the roof trusses. This could be for fink trusses in a house construction or queenpost trusses for a garage.

Structural engineers certify and design roof trusses. This is the right way to fix truss clips connecting the rafter and wall plate. If rafter construction is used instead of roof trusses and the roof covering is regular sheeting or tiles. This rafter truss calculator has a range of applications including being used as a wood truss calculator roof truss calculator roof rafter calculator scissor truss calculator or for roof framing.

Pitched roof timber sizes. We usually opt for the 35mm thickness in timber when designing standard roof trusses. 8d ring shank nails should be used instead. The minimum thatch layers and thickness vary depending on the type of grass or reed used for thatching.

The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. Building roof trusses for your home. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. Never attach roof sheathing with staples.

Roof truss factors to consider. Meanwhile the 46mm thickness option is used for attic trusses due to fire regulation guidelines. The typical thickness range for sheathing is 3 8 to 3 4 inch. Fine thatching grass or reed should have a 1 2 2 5 mm stem butt diameter.

When it comes to using osb or plywood for gussets vogt says that osb is more commonly used. The thickness of the material used for the gusset also affects the span rating that is how far apart the trusses can be spaced along the roof.