How Many Sheets of Plywood for 500 Square Feet?

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

Wall area compared

The same wall sheathing question at every common area. House wrap is quoted off the gross wall with ten percent for laps, so it does not fall when openings are deducted, because you wrap over an opening and cut it out afterwards.

What else matters here

Eighteen sheets and 11.5 lb of 8d common nails. The nail figure is the one worth reading, because it is counted the way an inspector counts it rather than the way a box is sold.

The calculator puts 64 nails in a sheet at 16 in framing: six inches apart all the way round the edges and twelve inches apart through the field. That pattern is not decoration. On a braced wall the edge nailing is what makes the panel act as a shear panel, and a panel nailed at twelve inches round the edge is not the panel the drawing specified even though it looks identical from three feet away.

So order nails against the pattern rather than against a feeling. Eleven and a half pounds sounds like a lot for eighteen sheets and it is exactly what a full nailing schedule uses. Running out halfway is the common way a wall ends up with the edges nailed at whatever spacing was left in the bag.

What this calculator assumes

• A sheet is 4 by 8, which is 32 square feet, so three and an eighth sheets cover a square.
• Openings come off in full here, not at half. A window hole in a sheathed wall is a real hole and the offcut around it is what the waste line is for.
• The nail count is the fastener schedule rather than a rule of thumb: six inches around every edge and twelve inches into the framing in the field, so a sheet at 16 inch spacing takes 64 nails and one at 24 inch spacing takes 56. Eight penny common runs about 100 nails to the pound.
• Subfloor adhesive is figured on the linear feet of joist under the sheets, at about 84 feet of quarter inch bead from a 28 ounce tube, which is the size subfloor adhesive actually comes in.
• Roof sheathing wants H clips in each bay along the unsupported joint between rafters, which is four per sheet at 24 inches on center. At 16 inches most panel thicknesses do not need them, so the list leaves them off below 19.2 inch spacing.
• A subfloor gets screwed rather than nailed on most jobs, so the list carries the same fastener count in number eight screws at about ninety five to the pound and leaves the nail line under it as the alternative. Only one of those two lines gets bought.
• Thickness does not change the count, only the price and the span rating. Check the panel span rating against your framing spacing before you buy the thin one.

Questions people ask

Other common sizes