Deck Cost Breakdown: Materials & a Worked Estimate
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A deck is a long list of small purchases, and the final number depends on your local prices, the material you choose, and how much of the work you do yourself. This guide shows how to build an estimate line by line: what quantities to count, how to get them from the Deck Calculator, and what a worked example looks like for a 16 × 12 ft deck.
The materials list, line by line
Every deck needs the same categories of materials, whatever its size. Count each one separately, then add them up.
| Item | What to count | How to get the quantity |
|---|---|---|
| Decking boards | Surface area ÷ board width, plus waste | Deck Calculator |
| Joists | One every 16 in across the width, plus one | Deck Calculator |
| Ledger, rim, and beam boards | Perimeter and beam lines | Your deck plan |
| Posts and footings | One per beam end and span | Deck plan and span tables |
| Concrete | Volume of each footing hole | Concrete Calculator |
| Fasteners and hangers | Per joist crossing and connection | Roughly 330 screws per 100 ft² |
| Railing and stairs | Linear feet of rail, number of steps | Measure the open sides |
| Permit and inspection fees | Local flat fee or a rate by area | Your building department |
Quantities for decking and joists use the same 16 in joist spacing and 12 ft boards as the calculator. Framing and footing quantities depend on your design and local code.
Worked example: a 16 × 12 ft deck
Take a 192 ft² deck attached to the house along one 16 ft side. The Deck Calculator gives 39 boards (12 ft, 5.5 in wide, with 10% waste) and 10 joists. The other quantities are assumptions for a typical low deck: 5 2×8×16 boards for the ledger, rim, and beams, 6 posts on 6 footings, and railing on the three open sides (40 ft). Each footing is a 12 in diameter hole 36 in deep, which takes about 2.4 ft³ of concrete, or 24 bags for all 6.
| Item | Quantity | Example price | Line total |
|---|---|---|---|
| Decking boards (16 × 12 ft, 5.5 in) | 39 × 12 ft boards | $15 | $585 |
| Joists, 2×8×16 | 10 | $30 | $300 |
| Ledger, rim, and beam boards, 2×8×16 | 5 | $30 | $150 |
| Posts, 6×6×8 | 6 | $25 | $150 |
| Joist hangers, bolts, flashing | allowance | - | $150 |
| Concrete for footings, 80 lb bags | 24 | $7 | $168 |
| Deck screws | 2 boxes (~634 screws) | $30 | $60 |
| Railing | 40 linear ft | $40/ft | $1,600 |
| Total (materials only) | $3,163 |
Placeholder prices for illustration only. Pressure-treated decking at the example price gives about $16 per square foot of deck in materials. Stairs, permits, tools, delivery, tax, and labor are extra.
How the decking material changes the total
Everything under the surface is the same for any decking, so the choice of boards is the biggest lever. Keeping the same 39 boards and swapping only the price shows how much it matters at the example prices.
| Decking | Example price per 12 ft board | Decking cost | Estimated materials total |
|---|---|---|---|
| Pressure-treated wood | $15 | $585 | $3,163 |
| Composite | $55 | $2,145 | $4,723 |
Wood costs less up front but needs sealing or staining every year or two, and composite costs more now with far less upkeep. Compare the totals over 10 to 15 years, adding the stain, sealer, and time for wood, before you decide. The Deck Calculator page compares lifespans and upkeep for each material.
What changes the cost most
- Height. Tall decks need longer posts, bigger footings, bracing, stairs, and more railing. A ground-level deck can skip the railing in many places.
- Shape. Diagonal boards, picture-frame borders, and curves add waste and labor. Use 15% or more waste for diagonal layouts.
- Railing. Railing is priced per linear foot and can rival the decking cost on a small, high deck.
- Local code. Frost depth sets the footing depth, and snow and wind loads can call for larger lumber or closer joists.
- Labor. A contractor's quote adds labor, equipment, and overhead to the materials above. Ask for an itemized estimate so you can compare it with your own list.
How to build your own estimate
- Design the deck. Decide the size, height, shape, and how it attaches to the house.
- Run the Deck Calculator for boards and joists, and the Concrete Calculator for footings.
- List the rest from your plan: posts, beams, ledger, hangers, railing, and stairs.
- Get real prices. Ask two or three suppliers for current prices on the exact items, including delivery.
- Add a contingency. Ten to fifteen percent covers waste, mistakes, and price changes.
- Add permit and inspection fees, then divide the total by the deck area to get your cost per square foot.
Ways to save without cutting corners
- Match board length to the deck dimension to cut seams and waste. A 16 ft deck with 16 ft boards needs no butt joints.
- Keep the design rectangular and low, which reduces railing, framing, and labor.
- Buy lumber together from one supplier and ask about a project discount or free delivery.
- Choose a mid-range material you can maintain, since a neglected wood deck costs more in the long run.
- Spend on the parts you can't easily change later: footings, framing, flashing, and fasteners.
Related guides and calculators
Frequently asked questions
It depends on size, height, decking material, railing, local lumber prices, and whether you hire a contractor. The reliable way to estimate is to list every material, multiply each quantity by your local price, then add permits and any labor. The worked example on this page shows the method for a 16 × 12 ft deck.