Plywood Thickness For Metal Roofing

Sheet with varying thickness.

Plywood thickness for metal roofing.

A local roofer submitted a proposal to me for a roof placement that included replacing rotten plywood with 1 2 cdx. Metal roofing panels rated for architectural use attached to purlins horizontal pieces of wood or metal fastened to roofing trusses are structurally sound when installed according to your roofing manufacturer s instructions and local building codes. If you ensure the plywood is in good condition and well protected before placing the metal roofing you can expect the average life expectancy of your metal on plywood roof to be 40 70 years. This kind of plywood can be used on roofs with minimal load.

Steeper rather than flatter roofs will have lesser load per sq. I thought perhaps he made a mistake but no this is what he is proposing. Tips for installing metal roofing accessories. The minimum thickness of plywood used for roofing is 3 8 th of an inch.

Nearly all homes have a layer of plywood or. For many applications a layer of plywood underneath your metal roofing is an unnecessary expense. To secure it measure it roll it out over the plywood cut it to the dimensions of the roof with a roofing or utility knife and finally hammer it securely to the plywood with 1 2 inch roofing nails. Multi ply is a catchall term for plywood with seven or more plies.

Plywood typically comes in 4 8 ft. On top of this underlayment goes a slip which protects the material from tearing as the metal roof expands and contracts with changing weather. If you are installing metal roofing onto plywood it is even more imperative that you have a solid base to place the metal roofing on. May 26 2020.

The existing plywood on my roof is only 3 8. Selecting metal roofing trim. The thickness of plywood used for roof decking depends on the roof slope the spacing of rafters and the weight of other material to be put over the decking as well as the design load the. Plywood with fewer plies is weaker than a plywood with more plies even if they have the same thickness.

A half inch thickness is considered to be standard in a lot of areas and it should work just fine considering that it s deemed okay by the roofing contractor after considering the things above. This plywood is strong and durable enough for use in roofing framing and other exterior structural projects. Manufacturers express the thickness of metal panels as their gauge with 22 gauge being the thickest and 29 gauge the thinnest of traditionally sold metal roof and wall panels. 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.