How many screws to fasten a sheet of plywood?
A 4x8 sheet takes 80 fasteners at 6" round the edges and 12" through the field. Counts for the other common patterns and sheet sizes.
A 4' × 8' sheet takes 80 fasteners at 6" edges and 12" field.
48 of them go round the perimeter and 32 through the field into the intermediate framing.
How that is worked out
- The perimeter is fastened tightest, because that is where a panel lifts and where the shear load goes: a fastener every 6" round all four edges gives 48.
- The middle of the sheet takes a grid at 12" both ways, which adds 32.
- 48 + 32 = 80 per sheet. The corners are counted once, not twice, which is why it is not simply the two edge counts added up.
Fasteners per sheet, by pattern
| Edge spacing | Field spacing | 4×8 sheet | 4×10 sheet | 4×4 sheet |
|---|---|---|---|---|
| 4" | 8" | 144 | 174 | 84 |
| 6" | 12" | 80 | 96 | 48 |
| 6" | 6" | 153 | 189 | 81 |
| 8" | 16" | 54 | 63 | 33 |
Worth knowing
- 6" edges and 12" field is the common default for wall and roof sheathing. It is not universal: a shear wall on an engineered plan can call for 4" or even 3" edges, and that spacing is structural — it is on the drawing for a reason and is not yours to relax.
- Keep fasteners back about 3/8" from a panel edge. Closer and they break out the edge ply, which is the same as not being there.
- Leave a gap between sheets — 1/8" is the usual call. Sheathing that is butted tight has nowhere to go when it takes on moisture and it buckles.
- The field count here is a full grid, which is what a panel screwed down to a solid substrate takes. Sheathing is different: a field fastener can only go where a stud or a joist is, so a 4x8 sheet on studs at 16" centres takes fewer field fasteners than the grid suggests. Use the grid figure for a solid substrate and count the framing members for sheathing.
- This counts fasteners, not framing. What the panel is fastened *to*, and how much of it there is, comes off the framing plan.
Work out your own numbers
- Fastener calculator
Screws or nails for a sheet good on an edge-and-field pattern, with the box count to buy.
- Wall framing stud count
Field studs at 16" or 24" on centre, corner studs, and the king and jack studs every opening adds.
Related questions
- How many screws for a 4x8 sheet of plywood?
- 80 at the usual 6" edge and 12" field pattern, counting a full grid through the middle of the sheet. Tighter patterns run a lot higher: 4" edges with an 8" field comes to 144. Fastening to framing rather than to a solid substrate needs fewer, because the field fasteners can only go where a stud or a joist actually is — see the note above.
- Should I use screws or nails for sheathing?
- Nails, almost always, and specifically the nail the plan or the code table names. Sheathing nails are sized and spaced to a tested assembly, and a screw of similar diameter is more brittle in shear — it resists withdrawal better and racking worse. Screws belong in subfloor, where squeak-free withdrawal resistance is the point and a construction adhesive is doing the real work.
- How far apart should subfloor screws be?
- 6" round the edges and 12" in the field is the usual specification, the same pattern as wall sheathing, and always over a bead of subfloor adhesive. The adhesive stops the squeak; the screws hold the sheet down while it cures.