How Thick Roofing Plywood

Roofs are framed with rafters or trusses which are rafters joined by internal braces so they install as a single component.

How thick roofing plywood.

Severe weather 1 2 in common douglas fir plywood sheathing application as 4 x 8. The most common plywood uses include support for floors walls roofs and garages in residential construction. That s considered to be the minimum. 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.

Rafters that are slightly farther apart might require inch or 5 8 inch thick plywood. 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. That s considered to be the minimum. When this is the case experts recommend a 5 8 inch thick sheet.

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. 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.