Roof Plywood Needed

Rafters that are slightly farther apart might require inch or 5 8 inch thick plywood.

Roof plywood needed.

Keep in mind that the load of the roof still plays a role in the plywood thickness. Finding the number of sheets of plywood needed for a floor wall ceiling or cabinet begins with finding the area that needs to be covered. Roof sheathing thickness unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. A 4 8 sheet of plywood is 32 ft 2.

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. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. When this is the case experts recommend a 5 8 inch thick sheet. Area can be found by multiplying the length and width of the space in feet.

If you mix thicknesses of plywood it will cause a problem eventually and the thicker sheathing will be noticeable probably within a month. One sheet 32 ft this basically calculates the number of sheets needed for a gable roof. Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb. Find the square footage of each space and add together to find the total square footage needed.

And this will reduce the life of the shingles tar paper and roof. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails. 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. Metal roofing is also available in the form of shingles.

The calculation is based on that the plywood or osb oriented strand board sheets are of a 4 x 8 size. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood. For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended. Continue adding panels until the roof is covered.

For example if your roof is 1 500 ft 2 then it will take 47 sheets of plywood to sheath it. 3 8 should be replaced optimally but it would be better to use all the same thickness sheathing than to mix them. With edge support and the same snow load 3 8 inch osb can be used. So dividing the area of the roof by 32 will give you the number of sheets needed.

Once you have the area you can divide by the area of a sheet of plywood to find the number of sheets needed. That s considered to be the minimum. You may need to cut panels to fit angles using a circular saw with a metal saw blade.