How to Figure Out Much Plywood Use on a Roof

- The size of the roof deck (length x width)

- The spacing between the rafters or trusses

- The thickness of the plywood

Once you have this information, you can use the following formula to calculate the amount of plywood you will need:

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Number of sheets of plywood = (Length of roof deck x Width of roof deck) / (Spacing between rafters or trusses x Area of one sheet of plywood)

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For example, if you have a roof deck that is 20 feet long and 12 feet wide, with rafters that are spaced 16 inches apart, and you are using 1/2-inch thick plywood, you would need the following number of sheets of plywood:

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Number of sheets of plywood = (20 ft x 12 ft) / (16 in x 32 sq ft) = 10 sheets

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When purchasing plywood, it is always a good idea to buy a few extra sheets in case of any mistakes or damage.

Here are some tips for installing plywood on a roof:

- Start by installing the plywood at the eaves of the roof.

- Overlap the edges of the plywood by at least 1/4 inch.

- Fasten the plywood to the rafters or trusses with nails or screws.

- Make sure that the nails or screws are long enough to penetrate the plywood and the rafters or trusses by at least 1 inch.

- Stagger the joints between the sheets of plywood.

- Use a saw to cut the plywood to size.

- Be careful not to damage the plywood when cutting it.