Deck material list: what to buy for a 12x16 deck
A deck order has more lines than most first-timers expect, and the cheap ones (hangers, flashing, fasteners) stop the job when they are missing. Here is a full list for one example deck, with the arithmetic shown so you can redo it for your own size.
The example deck
A 12 ft by 16 ft attached deck: 16 ft along the house, 12 ft out. Joists run out from the house at 16 inches on centre, decking runs parallel to the house, and the outer edge sits on a beam carried by three posts. Foundation footings are 12 inches across and 42 inches deep, which is a typical northern frost depth; yours comes from your building department (see the footing depth guide).
Total area is 192 sq ft. Change the size and every line below scales, which is what the calculators linked in each section do for you.
The list, line by line
| Item | How it is counted | Quantity |
|---|---|---|
| Decking boards | 144 in of width / (5.5 in board + 3/16 in gap) = 25.3 rows, plus 10% waste | 28 boards, 16 ft |
| Joists | 16 ft x 12 / 16 in spacing = 12 bays, plus 1 | 13 joists, 12 ft |
| Ledger | One board the length of the deck, bolted to the house | 1 board, 16 ft |
| Outer rim / band joist | Closes the ends of the joists | 1 board, 16 ft |
| Beam | Doubled boards on top of the posts | 2 boards, 16 ft |
| Posts | One at each beam end and one in the middle (8 ft apart) | 3 posts |
| Footings | One per post | 3 footings |
| Concrete | 3 x 2.75 cu ft = 8.25 cu ft / 0.45 cu ft per 60 lb bag | 19 bags, 60 lb |
| Joist hangers | One per joist at the ledger | 13 hangers, with the hanger nails |
| Post bases and beam caps | One of each per post | 3 + 3 |
| Ledger flashing | The full ledger length, lapped under the house wrap | 16 ft |
| Ledger fasteners | Spacing comes from the joist span (see the ledger guide) | Per the DCA 6 table |
| Decking fasteners | 26 rows x 13 joists x 2 screws, or one hidden clip per crossing | About 700 screws, or 2 boxes of clips |
| Railing (3 open sides) | 12 + 12 + 16 ft, less any stair opening | About 40 linear ft |
Count your own boards with the deck board calculator, joists with the deck joist calculator, concrete with the deck footing calculator and screws or clips with the deck fastener calculator.
Buy extra of the right things
The 10% waste on boards covers cuts at the ends and the occasional bowed board. Buy the boards in one batch, because composite and even pressure-treated lumber differ from lot to lot in colour and moisture content. Hangers, post bases and structural screws are cheap relative to a second trip, so buy a few spare.
Order the framing in lengths that avoid joints. A 16 ft beam from two 16 ft boards needs no splice over a post; a 20 ft run would need a splice, and splices must land over a post.
Check the list against your plan
Before ordering, hand the list to the building department or your lumberyard with the framing plan. Joist and beam sizes are not on this list on purpose: they come from the span tables, not from the deck area. Look them up in the joist span chart and the beam span chart, then price the sizes you land on with the deck cost calculator.
What this list leaves out
- Stairs: stringers, treads and risers depend on the height off the ground. See the deck stair code guide.
- Permit and inspection fees: see the deck permit guide.
- Gravel for footing bases, a dumpster and tool rental.
- Stain or sealer for wood decks; the deck stain calculator sizes it.
For a priced version of the same deck, run the deck cost calculator, and for the build sequence, follow how to build a deck.
Materials & tools for this job
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ShunHong Outdoor Solid Composite Decking Boards Color Samples Pack
$15.99
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430pcs Hidden Deck Fasteners for Decking Board, Composite Deck Clips Plastic Hidden Fastners with Metal Screws,Universal Nylon Clips for Composite Decking Cover 200 sq. ft of Deck (430)
$36.99
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8 Pcs ABS Deck Spacer Tool, 4 Thicknesses Orange Deck Board Spacers
$9.99
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Deck Plus Deck Screws, #10 x 2-1/2in, 365 Pieces,5 Lb Box, Tan
$29.98
Check price on AmazonPrices as of Oct 13, 2026, 4:41 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Shopping for someone? See our guide to gifts for woodworkers.
Frequently asked questions
How do I make a deck material list?
Start from the deck size. Count decking boards from the width divided by board width plus gap, add 10% waste, count joists from the length divided by spacing plus one, then add the ledger, rim, beam, posts, footings, hangers, flashing and fasteners. The table above does this for a 12x16 deck.
How many deck boards do I need for a 12x16 deck?
About 28 boards of 16 ft when laid parallel to the 16 ft side with 5.5 inch boards and a 3/16 inch gap, including 10% waste. That is 448 linear feet of decking. Wider or narrower boards, a bigger gap or a diagonal layout change the count, so rerun it in the deck board calculator.
How many joists does a 12x16 deck need?
13 joists at 16 inches on centre across 16 ft, which includes the two end joists. At 12 inches on centre it is 17, and at 24 inches it is 9. Check the decking maker's maximum spacing first, because it sets which of those three counts you can actually use on the deck.
How many bags of concrete do I need for deck footings?
Three 12 inch footings 42 inches deep take about 8.25 cubic feet, which is 19 bags of 60 lb concrete. Add about 10% for spillage and for footing holes that end up wider than planned. Deeper frost depths in colder regions raise the bag count quickly, so check the depth your building department requires before ordering.
What do people forget when buying deck materials?
Joist hangers and their nails, ledger flashing, post bases and beam caps, structural ledger fasteners and gravel for footing bases. None is expensive, but missing any of them stops the build. Go through the table against your framing plan before you place the order, and pick up a few spares of each small part.
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