How Thick Roofing Plywood

Severe weather 1 2 in common douglas fir plywood sheathing application as 4 x 8.

How thick roofing plywood.

Unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. Rafters run from the peak of the roof. That s considered to be the minimum. Roofs are framed with rafters or trusses which are rafters joined by internal braces so they install as a single component.

When used for roofing plywood panels are covered and protected by a variety of building materials that keep the elements at bay including roof felt underlayment flashing and shingles. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood. Osb and plywood come in thicknesses ranging from 5 16 to 3 4 inch and the thickness needed for a particular roof depends on several factors including rafter spacing expected load and roof design. The most common plywood uses include support for floors walls roofs and garages in residential construction.

Keep in mind that the load of the roof still plays a role in the plywood thickness. When this is the case experts recommend a 5 8 inch thick sheet. This minimum will only work if the rafters are set 16 inches apart at most and if the roof doesn t have too much load.