10x12 Deck Material List: Boards, Joists, Screws, Footings
A 10x12 deck (120 square feet) with the boards running the 12 ft way needs 25 deck boards of 12 ft, 10 joists of 10 ft and about 440 screws. With the boards running the 10 ft way instead, the same deck takes 29 boards of 10 ft, 9 joists of 12 ft and 468 screws. Both lists are below, and the deck materials calculator opens on this deck.
Part of the project planner: Planning and building a deck.
A 10 × 12 ft deck is the compact one of the common sizes. The deck planner reckons a table for four fits about 10 × 10 ft, so this size gives that table plus a 2 ft strip for a grill or a way past the chairs.
10x12 deck material list, boards running the 12 ft way
This is the usual layout: the 12 ft side along the house, the boards parallel to it, and the joists spanning the 10 ft out from the house.
| What to buy | How much | How we worked it out |
|---|---|---|
| Deck boards, 12 ft, 5.5 in wide | 25 | 22 rows across the 10 ft width, with 10% waste |
| Joists | 10 | 10 ft long, at 16 in on center along the 12 ft side |
| Deck screws | 440 | Two per board at each joist |
| Joist hangers, up to | 20 | One per joist end hung from a ledger or rim |
| Joist tape | 100 ft | On the top of every joist |
| 80 lb bags | 26 | Footing concrete, for example 6 footings, 12 in across, 3 ft deep. Your plans set the number |
| Stain or sealer | 1 gal | One coat at about 200 sq ft a gallon (2 gal for two coats) |
Beams, posts, the ledger board and railings come from your plans and local code.
How the numbers are worked out
- Rows: the 10 ft width is 120 in. Each row takes 5.625 in (a 5.5 in board plus a 1/8 in gap), and 120 ÷ 5.625 = 21.3, so 22 rows.
- Boards: 22 rows plus 10% waste is 24.2, rounded up to 25 boards of 12 ft.
- Joists: the 12 ft side is 144 in, and 144 in ÷ 16 in = 9 spaces, which needs 10 joists.
- Screws: 22 rows × 10 joists × 2 = 440.
The same deck with the boards running the 10 ft way
Turned the other way the boards are 10 ft long: 29 boards of 10 ft, or only 15 boards of 20 ft, because each 20 ft board is cut into two rows.
| Board direction | Rows | Boards to buy | Joists | Screws |
|---|---|---|---|---|
| Boards run the 12 ft way | 22 | 25 of 12 ft | 10 of 10 ft | 440 |
| Boards run the 10 ft way | 26 | 29 of 10 ft | 9 of 12 ft | 468 |
In the calculator the first box, deck length, is always the way the boards run, so swap the two numbers to see the other layout.
Which board length to buy
Twelve-foot boards fit this deck exactly: one board is one row, with no joints and only the ends to trim. Sixteen-foot boards give the same count of 25 but leave a 4 ft cutoff from every board, and 8 ft boards need a joint in every row and come to 37.
| Board length (boards run the 12 ft way) | Boards to buy | Joints |
|---|---|---|
| 8 ft boards | 37 | A joint in every row |
| 10 ft boards | 30 | A joint in every row |
| 12 ft boards | 25 | None: one board is one row |
| 16 ft boards | 25 | None, with a 4 ft cutoff from each board |
| 20 ft boards | 25 | None, with an 8 ft cutoff from each board |
With narrower 2x4 boards (3.5 in) this deck takes 38 boards of 12 ft, and with wide 2x8 boards (7.25 in) it takes 19.
Joists and screws by spacing
The joists are only 10 ft long, the shortest of the rectangular lists, so this is the easiest frame to carry and to set. There are 10 of them, so allow up to 20 hangers and 100 ft of joist tape.
| Joist spacing | Joists, boards the 12 ft way | Screws | Joists, boards the 10 ft way | Screws |
|---|---|---|---|---|
| 12 in | 13 | 572 | 11 | 572 |
| 16 in | 10 | 440 | 9 | 468 |
| 24 in | 7 | 308 | 6 | 312 |
Footing concrete by number of footings
The number of footings comes from your plans, so the list above uses 6 only as an example. For footings 12 in across and 3 ft deep, with 10% extra:
| Footings in your plans | 80 lb bags of concrete |
|---|---|
| 4 footings | 18 |
| 6 footings | 26 |
| 8 footings | 35 |
| 9 footings | 39 |
| 12 footings | 52 |
Checks before you start
- Nothing on this list is longer than 12 ft, which makes it the easiest of these orders to haul yourself. Still compare a delivery charge with the trips it saves.
- Get a permit and find out the frost depth for your footings.
- Size the joists for the 10 ft span from the span tables for your lumber.
- Use hot-dip galvanized or stainless fixings for treated lumber.
Other sizes: 8x8 deck, 12x12 deck, 12x16 deck, 12x20 deck, 14x20 deck, 16x16 deck. See also the materials list for a deck and how many deck boards you need. The 10x12 deck boards page counts the boards running the 10 ft way. These are estimates for planning.
Frequently asked questions
How many deck boards for a 10x12 deck?
25 boards of 12 ft when the boards run the 12 ft way (22 rows across the 10 ft width, with 10% waste). If the boards run the 10 ft way it is 29 boards of 10 ft in 26 rows.
How many joists for a 10x12 deck?
10 joists of 10 ft at 16 inches on center when the boards run the 12 ft way, or 9 joists of 12 ft when the boards run the 10 ft way. The span table for your lumber decides the joist size and whether a beam is needed.
How many screws for a 10x12 deck?
About 440: 22 rows × 10 joists × 2 screws. With the boards the other way it is about 468.
Is a 10x12 deck big enough for a table and chairs?
It is 120 square feet. As a rule of thumb a table for four needs about 10 × 10 ft, so a 10 × 12 deck fits one with a little room to spare. Mark it out on the ground and put the furniture inside before you decide.
How much concrete for the footings of a 10x12 deck?
It depends on the number of footings in your plans. As an example, 6 footings 12 inches across and 3 feet deep take about 26 bags of 80 lb mix. Your frost depth and plans set the real size and number.
More guides
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.
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