Enter the deck's size, height and decking to see what the materials come to, and where the money goes.
22 items for a 16 × 12 ft attached deck with 5/4 x 6 pressure-treated decking: 2x10 joists at 16 in, one 2-ply 2x8 beam and 4 footings 48 in deep under 4x4 posts (OBC 2024 Part 9), with a guard and stairs.
| Qty | Item | Line total |
|---|---|---|
| 30 | 5/4x6 × 16 ft treated decking | $449.10 |
| 13 | 2x10 × 12 ft treated lumber | $285.74 |
| 40 bags | Quikrete 80 lb Concrete Mix | $279.20 |
| 90 | 2x2 × 36 in balusters | $178.20 |
| 3 boxes | 2-1/2 in Deck Screws | $104.94 |
+ 17 more items in the full list: hangers, ties, screws, concrete and the rest.
Where these numbers come from. The deck's guard and footing depth follow the Ontario Building Code 2024, Part 9, with its article numbers. Joists, beams and posts are sized from the CWC Prescriptive Residential Exterior Wood Deck Span Guide (2016) (incised treated lumber; 1- to 3-ply beams; 4x4 posts up to 6.5 ft, where the plan asks your building department to confirm them, since OBC 9.17.4.1 calls for 6x6); footing diameters use the US AWC DCA 6 table, for reference, since neither NBC Part 9 nor the guide has one for decks. The US reference values are still being checked line by line against the code book. Snow: the calculator doesn't know your town, so it uses Part 9's minimum deck load of 1.9 kPa (40 psf) (OBC 9.4.2.3), the load the guide is for. A town with heavy snow can need more: pick yours below, or have it checked; the full planner looks it up. Treat the result as a starting point and confirm your design with your local building department before you build. OBC 2024's Part 9 is based on NBC 2020. Joist, beam and post tables: Canadian Wood Council, Prescriptive Residential Exterior Wood Deck Span Guide (2016), designed to CSA O86-14 and NBC 2015.
The calculator designs the deck the way the 16Span planner does, to the Ontario Building Code 2024, Part 9: footings 1.2 m down unless the deck is small enough to be exempt, and a guard and balusters above 600 mm, with joists, beams and posts sized from the Canadian Wood Council's deck span guide (1- to 3-ply beams, and 4x4 posts up to 6.5 ft where the plan asks the building department to confirm them). Then it takes off every piece of the framing: joists and rims nested onto stock lengths, beam plies, posts, decking with 10% extra for culls, and the hangers, ties, screws and concrete that hold it together, with stairs when the deck is more than a step up.
Every price is an illustrative big-box estimate in US dollars, not a live price, and tax is not included. Canadian prices, and your store's, will differ. Treat the total as a budget figure for comparing options, not a quote.
Decking is usually the largest single cost. Composite costs more up front but needs no staining, and it fastens with hidden clips. Check the maker's required joist spacing before you buy: some boards call for 12 in on center.
Height changes the posts, the guard and the stairs. Width changes the joist size and the beam. Deeper footings for frost add concrete. The full plan lets you edit every line and look up store prices near you.
For a 16 × 12 ft deck attached to the house, 3 ft up with a guard and stairs in Ontario, on 6x6 posts and footings 48 in deep, 16Span's estimate is about $2,087.23 with 5/4 x 6 pressure-treated decking, $2,224.51 with 2x6 decking and $3,208.51 with composite. These are estimated big-box prices in US dollars, before tax. Prices in Canada and at your local store will differ.
About 32 boards of 5/4 x 6, most of them 16 ft, for the 16 × 12 ft deck above. That includes the stair treads and 10% extra for culls and end damage. The planner shows the full cut list, board by board.
No. They are illustrative estimates of big-box store prices in US dollars, built into 16Span, not live prices. In the planner you can look up store prices near your postal or ZIP code and edit any price. Always confirm in store before you buy.
Tax, delivery, tools, permits and site prep such as gravel. Footing concrete is counted for the depth the design uses: in Ontario, holes dug to 48 in (1.2 m), as OBC 2024 Table 9.12.2.2 asks where the soil isn't known, unless the deck is small enough to be exempt (9.12.2.2.(7)).
The full materials list with every line and its reasoning, the blueprint, a 3D model, the code check and the build steps.