Flat Roof Plywood Sheathing

As a quick primer in plywood each side is rated from a to d.

Flat roof plywood sheathing.

Up until 2000 plywood held the majority of the market for wall roof and floor sheathing when it was surpassed by osb which as of 2018 held about 75 of the market share. Installing sheathing on a flat roof is much easier than working on a peaked roof. That s considered to be the minimum. The common grade of plywood for roof sheathing is cdx.

Follow these 5 simple construction steps for roof sheathing. A 4 8 sheet of plywood is 32 ft 2. A strong resilient roof is a home s first line of defense when the roof deck is exposed to weather. A is smooth and knot free while d the lowest quality has missing knots and cracks.

Odds are that if you pass a housing development of wood framed houses it will have osb oriented strand board as exterior sheathing. 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. Plywood is typically. Once you have the area you can divide by the area of a sheet of plywood to find the number of sheets needed.

So dividing the area of the roof by 32 will give you the number of. When you count sub floors roofs and wall sheathing osb claims about 70 of the wood sheathing market in north america over plywood. The sheathing is the base you lay over the rafters that holds the roofing felt and shingles. Before lumber companies began selling osb the standard choice for sheathing a roof with a 24 inch rafter spacing was 1 2 inch cdx plywood the letters cdx indicate that it is construction grade.

That s considered to be the minimum. Never attach roof sheathing with staples. 8d ring shank nails should be used instead. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame.

One side is usually better quality than the other c in this case. Plywood is made with an odd number of layers for optimal strength and performance. Sheathing should be a minimum of 19 32 inch thick. Plywood is a bit more expensive but is usually stronger and is often selected in cases where the roof covering is heavier such as for slate clay or concrete tile roofs.

If your roof has triangles and other shapes you ll need to use a calculator to find the square footage. One of the nice things about plywood is the variety of options you can buy. It should be placed up on the roof.