Boards for a 8 × 8 ft deck, by board length
An 8 × 8 ft deck is a small landing or a spot for a bistro table and two chairs. With 5½ in boards and 1/8 in gaps the deck has 18 rows, which is 144 ft of decking before waste. These counts include 10% waste:
| Board length | Boards to buy | Total length bought |
|---|---|---|
| 8 ft boards | 20 | 160 ft |
| 10 ft boards | 16 | 160 ft |
| 12 ft boards | 14 | 168 ft |
| 16 ft boards | 10 | 160 ft |
| 20 ft boards | 8 | 160 ft |
Waste and layout
| Layout | Waste | 12 ft boards | 16 ft boards |
|---|---|---|---|
| Straight, careful installer | 5% | 13 | 10 |
| Straight (typical) | 10% | 14 | 10 |
| Diagonal or picture-frame border | 15% | 14 | 11 |
Joists and screws
Joists run the 8 ft width and are spaced along the 8 ft length.
| Joist spacing | Joists | Screws |
|---|---|---|
| 12 in on center | 9 | 324 |
| 16 in on center | 7 | 252 |
| 24 in on center | 5 | 180 |
That is just the decking surface, for a 64 ft² deck. Posts, beams, footings, ledger, railings and stairs are extra, and a permit is usually required.
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Tools & materials for this project
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Frequently asked questions
How many deck boards for a 8x8 deck?
With 5½ in boards, 1/8 in gaps and 10% waste, you need 14 boards of 12 ft, or 10 boards of 16 ft. That is 18 rows of decking across the 8 ft width.
How many joists does a 8x8 deck need?
At 16 in on center, 7 joists running the 8 ft width. At 12 in it is 9, and at 24 in 5. Joist size and span must follow your local building code.
How many screws for a 8x8 deck?
About 252 screws: two at every joist for each board. Buy a few extra, since they strip and get dropped.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.