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.
Roof plywood needed.
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.
Continue adding panels until the roof is covered.
Once you have the area you can divide by the area of a sheet of plywood to find the number of sheets needed.
Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails.
If you mix thicknesses of plywood it will cause a problem eventually and the thicker sheathing will be noticeable probably within a month.
Area can be found by multiplying the length and width of the space in feet.
You may need to cut panels to fit angles using a circular saw with a metal saw blade.
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.
For example if your roof is 1 500 ft 2 then it will take 47 sheets of plywood to sheath it.
And this will reduce the life of the shingles tar paper and roof.
With edge support and the same snow load 3 8 inch osb can be used.
That s considered to be the minimum.
So dividing the area of the roof by 32 will give you the number of sheets needed.
A 4 8 sheet of plywood is 32 ft 2.
Rafters that are slightly farther apart might require inch or 5 8 inch thick plywood.
3 8 should be replaced optimally but it would be better to use all the same thickness sheathing than to mix them.
Roof sheathing thickness unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick.
Metal roofing is also available in the form of shingles.
Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood.
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.
It will support roof.
For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended.
Sheets of 7 16 inch thick with no edge support can be used in an area where the snow load is 30 pounds per square foot.
Find the square footage of each space and add together to find the total square footage needed.
Keep in mind that the load of the roof still plays a role in the plywood thickness.