Flat Roof Plywood Thickness

In roofing plywood can be used as roof decking.

Flat roof plywood thickness.

A local roofer submitted a proposal to me for a roof placement that included replacing rotten plywood with 1 2 cdx. Required dimensions of plywood for roofing. 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.

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. Loads will vary with the pitch of the roof. He said it s only a difference of 1 8 thickness. If you have any.

I thought perhaps he made a mistake but no this is what he is proposing. Most roofs will be sheathed in plywood at least 3 8 inch thick. Sheathing should be a minimum of 19 32 inch thick. A roof that lays practically flat will have a much heavier load than a steeper roof that allows rain snow and ice to roll right off.

Sheet with varying thickness. This kind of plywood can be used on roofs with minimal load. Roof decking is the material that lies on top of the main roofing structure and the underlayment and roof covering is applied on top. Whether you re looking for plywood pitched roofing materials flat roofing materials or accessories we ve got everything you ll need.

The minimum thickness of plywood used for roofing is 3 8 th of an inch. Unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. 8d ring shank nails should be used instead. 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.

That s considered to be the minimum. Plywood typically comes in 4 8 ft. Rafters that are slightly farther apart might require inch or 5 8 inch thick plywood. Steeper rather than flatter roofs will have lesser load per sq.

The typical thickness range for sheathing is 3 8 to 3 4 inch. The existing plywood on my roof is only 3 8. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads.