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Free plan · OBC 2024 Part 9

10 × 10 deck plan.

A free 10 × 10 ft attached deck, 5/4 x 6 pressure-treated plan designed to the Ontario Building Code 2024, Part 9: 2x8 @ 16 in o.c. joists, a 2-ply 2x6 beam and 4x4 posts on 14 in dia. round, 48 in deep footings, about $1,356 in materials at estimated big-box prices. Blueprint, 3D model, materials list, code check and build steps.

10 × 10 ft attached deck, 5/4 x 6 pressure-treated

Where are you building?

Results follow the Ontario Building Code 2024, Part 9.

Framing
Joists2x8 @ 16 in o.c.
Beam2-ply 2x6
Posts4x4
Footings14 in dia. round, 48 in deep
Ledger2x8 (2x8 minimum, at least as deep as the joists)

Estimated big-box prices (USD)before tax

Materials$1,355.75

A rectangular deck of 100 sq ft attached to the house with a ledger, 2x8 joists at 16 in on center on 1 beam line. The surface sits 36 in above grade. 20 items in the list below, every one with its quantity and why.

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.

013D model

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02Blueprint

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03Materials list

QtyItemEachTotal
Lumber$466.40
4 each2 in. x 4 in. x 14 ft. #2 Prime Ground Contact Pressure-Treated Lumber2 rails at 10'-3.5", 2 rails at 3'-2.5", 2 rails at 9'-8.5", 2 rails at 3'-9.5" → 2 boards cut 10'-3.5" + 3'-2.5"; 2 boards cut 9'-8.5" + 3'-9.5" (1'-11.5" total offcut).$11.28$45.12
2 each2 in. x 6 in. x 10 ft. #2 Prime Ground Contact Pressure-Treated Lumber2 beam plies at 10'-0" → 2 boards cut 10'-0" (0" total offcut).$10.98$21.96
11 each2 in. x 8 in. x 10 ft. #2 Prime Ground Contact Pressure-Treated Lumber1 ledger at 10'-0", 3 rim joists at 10'-0", 7 joists at 9'-9" → 4 boards cut 10'-0"; 7 boards cut 9'-9" (1'-9" total offcut).$13.98$153.78
2 each2 in. x 12 in. x 10 ft. #2 Prime Ground Contact Pressure-Treated Lumber4 stair stringers at 4'-2.25" → 2 boards cut 4'-2.25" + 4'-2.25" (3'-2.25" total offcut).$24.98$49.96
5 each4 in. x 4 in. x 8 ft. #2 Ground Contact Pressure-Treated Timber8 guard posts at 3'-6.75", 3 posts at 1'-10.25" → 4 boards cut 3'-6.75" + 3'-6.75"; 1 board cut 1'-10.25" + 1'-10.25" + 1'-10.25" (5'-10.5" total offcut).$12.98$64.90
66 each2 in. x 2 in. x 36 in. Pressure-Treated Square-End Baluster28'-2" of top rail ÷ 5.25 in (1.5 in baluster + 3.75 in clear, under the 4 in sphere rule) = 66 balusters.$1.98$130.68
Decking$271.92
2 each5/4 in. x 6 in. x 8 ft. Premium Pressure-Treated Decking Board22 boards in 22 rows across 100 sq ft, joints over joists and staggered; 8 tread boards. 2 tread boards at 3'-0" → 1 board cut 3'-0" + 3'-0" (2'-0" total offcut). 1 boards +10% for culls and end damage = 2.$7.98$15.96
27 each5/4 in. x 6 in. x 10 ft. Premium Pressure-Treated Decking Board22 boards in 22 rows across 100 sq ft, joints over joists and staggered; 8 tread boards. 22 decking boards at 10'-0", 6 tread boards at 3'-0" → 22 boards cut 10'-0"; 2 boards cut 3'-0" + 3'-0" + 3'-0" (1'-11.5" total offcut). 24 boards +10% for culls and end damage = 27.$9.48$255.96
Concrete$167.52
24 bagQuikrete 80 lb. Concrete Mix3 footings (14 in × 48 in = 4.28 cu ft → 8 bags each); an 80 lb bag yields 0.6 cu ft.$6.98$167.52
Hardware$180.10
9 eachSimpson Strong-Tie LUS ZMAX Galvanized Face-Mount Joist Hanger for 2x8One per joist end at the ledger: 9 2x8 joists and side rims frame into it.$1.98$17.82
18 eachSimpson Strong-Tie H2.5A ZMAX Hurricane TieTwo per joist at each beam crossing (one each side) for uplift: 9 crossings × 2.$0.88$15.84
3 eachSimpson Strong-Tie ABA ZMAX 4x4 Adjustable Post BaseOne per 4x4 post on a concrete footing (3); keeps end grain off the concrete.$11.98$35.94
3 eachSimpson Strong-Tie BC ZMAX Galvanized Post Cap for 4x4One per 4x4 post carrying a beam (3) to tie the beam down.$6.98$20.94
4 eachSimpson Strong-Tie LSCZ ZMAX Adjustable Stair-Stringer ConnectorOne per stair stringer (4) at the rim.$7.48$29.92
16 each1/2 in. x 8 in. Hot-Dip Galvanized Carriage Bolt with Nut and WasherTwo through-bolts per guard post: 8 posts × 2.$2.48$39.68
2 each10 ft. Galvanized Steel Z-Flashing10'-0" of ledger with 6 in laps between 10 ft pieces = 2.$9.98$19.96
Fasteners$194.87
1 boxFastenMaster LedgerLOK 3-5/8 in. Ledger Board Screw (50-pack)10'-0" of ledger, 2 staggered rows at 16 in o.c. = 16 screws → 1 × 50-pack.$49.97$49.97
3 boxSimpson Strong-Tie SD9112 #9 x 1-1/2 in. Connector Screws (100-pack)Screws for hangers (10 × 9) + ties (5 × 18) + post bases (8 × 3) + caps (12 × 3) + stringer connectors (10 × 4) = 280.$24.98$74.94
2 box2-1/2 in. Coated Deck Screws (5 lb box)22 rows × 9 joists × 2 + 8 tread boards × 4 stringers × 2 = 460 decking screws; 66 balusters × 4 = 264 → 724 screws at ~450 per box = 2.$34.98$69.96
Misc$74.94
3 rollSelf-Adhesive Joist Tape 1-5/8 in. x 50 ft11 joists, rims and beams ≈ 108 ft of tops ÷ 50 ft rolls = 3.$24.98$74.94
Estimated total, before tax$1,355.75

Prices are illustrative big-box estimates in US dollars, not a quote. Open the plan in 16Span to look up prices at your own store.

04Code check

Code check · Ontario, Canada

What the rules say

  • Verify
    Post size
    This plan uses 4x4 support posts, which the CWC Deck Span Guide allows up to 2.0 m (6.5 ft) tall under a 1- or 2-ply beam (note 5). OBC 2024 9.17.4.1.(2) calls for 6x6 posts (wood columns at least 140 × 140 mm) unless calculations show a smaller size is adequate; the guide's tables are engineered to CSA O86, but the building department may still ask for 6x6. Confirm before building. Railing posts can stay 4x4.
  • OK
    Guard
    The deck is 914 mm (36 in) above grade, more than the 600 mm at which OBC 2024 9.8.8.1.(1) requires a guard; a 914 mm (36 in) guard is included on the open sides, and OBC 9.8.8.3.(3) requires at least 900 mm for an exterior guard serving one dwelling unit where the surface is not more than 1,800 mm above grade. Openings must stop a 100 mm sphere (9.8.8.5.(1)), and nothing between 140 mm and 900 mm above the deck may make it climbable (9.8.8.6.(1)): vertical balusters, no horizontal rails in that zone.
  • OK
    Stairs
    5 risers of 183 mm (7.2 in) for a total rise of 914 mm (36 in), 267 mm (10.5 in) runs. OBC 2024 Table 9.8.4.1 allows private stairs a rise of 125–200 mm and a run of 255–355 mm — OK. One handrail is required: more than 3 risers on exterior stairs serving one dwelling unit (OBC 9.8.7.1.(3) and (4)).
  • N/A
    Joist cantilever
    Joists end flush over the outer beam; no cantilever.
  • Verify
    Footing depth
    Footings bottom out 1,219 mm (48 in) below grade: OBC 2024 Table 9.12.2.2 requires foundations at least 1,200 mm (47.2 in) deep, and not less than the depth of frost penetration, in clay or soils not clearly defined, and these meet it. The soil here is unknown, so the conservative row is used: rock, coarse-grained soil or silt can allow less (Table 9.12.2.2), and 9.12.2.2.(5) allows less where local experience shows it works. The table also wants them below the frost: confirm the local frost depth with the building department.
  • Verify
    Deck load
    OBC 2024 9.4.2.3: a deck serving one dwelling unit is designed for the specified snow load or 1.9 kPa (39.7 psf), whichever is greater; 9.4.2.2 gives the snow load as S = Cb × Ss + Sr (at least 1 kPa), from the site's Ss and Sr in MMAH Supplementary Standard SB-1. This plan has no Ss and Sr for the site, so its joists and beams are sized from the CWC Deck Span Guide’s tables, which are for a 1.9 kPa live load: look up the town's Ss and Sr in SB-1 Table 2, or confirm the design load with the building department.
  • Verify
    Span tables
    Joists, beams and posts are checked against the CWC Prescriptive Residential Exterior Wood Deck Span Guide (2016) (incised treated lumber, No. 2 or better, 1.9 kPa live load), engineered to CSA O86 for outdoor decks. The guide has no tables for footing size or ledger fastening, so those use the US AWC DCA 6 (2015 IRC edition) values for reference, not yet verified against the code book. The guide is not part of the building code: confirm the member sizes with your building department. 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.
Structure

Every size, checked

RoleSizeSpecies / gradeSpan / loadChecked against
Joists2x8 @ 16 in o.c.D.Fir-L / Hem-Fir / S-P-F, No. 2 or better, pressure-treated (incised)2.97 m (9 ft 9 in) ledger-to-beamCWC Deck Span Guide Table 3a, incised, No. 2 or better: 38 × 184 mm (2x8) joists at 400 mm (16 in) o.c. may span 3.21 m (10 ft 6.5 in) (Douglas Fir-Larch governs); design spans 2.97 m (9 ft 9 in) — OK, 0.24 m (0 ft 9.5 in) margin. No cross bridging: the guide's spans assume the decking braces the joists.
Beam2-ply 2x6D.Fir-L / Hem-Fir / S-P-F, No. 2 or better, pressure-treated (incised)max post spacing 1.48 m (4 ft 10.25 in); joist span 2.97 m (9 ft 9 in)CWC Deck Span Guide Table 5b, incised, joist span + cantilever up to 10 ft: a 2-ply 2x6 D.Fir-L / Hem-Fir / S-P-F beam may have posts up to 1.83 m (6 ft 0 in) apart (the table lists 2-ply 2x6 at 6 ft); design has 1.48 m (4 ft 10.25 in) between post centres — OK, 0.35 m (1 ft 1.75 in) margin.
Posts4x4D.Fir-L / Hem-Fir / S-P-F, No. 2 or better, pressure-treated (incised)tallest post 1 ft 10.25 in, top of footing to underside of beamCWC Deck Span Guide note 5: 4x4 posts up to 2.0 m (6.5 ft) high, 6x6 up to 3.66 m (12 ft), and 6x6 under a 3-ply beam; these 4x4 posts are up to 565 mm (22.3 in) under a 2-ply beam — OK. 4x4 posts are 89 × 89 mm; OBC 9.17.4.1.(2) requires wood columns at least 140 × 140 mm unless calculations show a smaller size is adequate (the CWC guide's engineered tables allow this 4x4, so 16Span asks the building department to confirm it). No lateral bracing is needed: the posts are 600 mm or less from the ground to the beam and carry a deck with no superstructure (OBC 9.17.2.2.(3)).
Footings14 in dia. round, 48 in deepConcrete; assumes 1500 psf soil bearingtributary area 29.6 sq ft per footing ≈ 1,479 lb at 50 psfNBC Part 9 and the CWC deck guide have no deck table for footing sizes (its Table 9.15.3.4. sizes footings for building columns); for reference, the US AWC DCA 6 Appendix Table B3 (1500 psf soil): the 30 sq ft row needs a round footing at least 14 in across and 6 in thick (the footing's own weight included); design has 14 in — OK, 0 in margin. Concrete 48 in thick — OK. (from AWC DCA 6, 2015 IRC edition; IRC 2021 not yet confirmed)
Ledger2x8 (2x8 minimum, at least as deep as the joists)D.Fir-L / Hem-Fir / S-P-F, No. 2 or better, pressure-treated (incised)carries the house end of joists spanning 9 ft 9 inOBC 2024 Part 9 has no prescriptive rule for fastening a deck ledger to a house: use an engineered or building-department-accepted ledger detail. For reference only, the US AWC DCA 6 Table 5 schedule: AWC DCA 6 Table 5 at the 10 ft joist-span column: 1/2 in lag screws at 18 in o.c. or through-bolts at 34 in o.c., staggered in two rows. It assumes a 2 in nominal solid-lumber house band joist. Fasten to the house rim joist only (not brick or stone veneer), with flashing above. (from AWC DCA 6, 2015 IRC edition; IRC 2021 not yet confirmed)

Assumptions

  • Sized from the span tables for a 10 × 10 ft deck 3 ft above grade, attached to the house with a ledger.
  • Designed to the Ontario Building Code 2024, Part 9 for a deck in Ontario: its guard, footing depth and post rules apply. Joists, beams and posts are sized from the Canadian Wood Council's deck span guide (1- to 3-ply beams; 4x4 posts up to 6.5 ft, which the building department is asked to confirm); footing sizes use the US AWC DCA 6 table for reference. Confirm the sizes with your building department. 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 town isn't known, so the snow load and frost depth are not looked up: the deck is designed for Part 9's 1.9 kPa (40 psf) minimum deck load, and a town with heavy snow can need more. Tell the planner where you are building to check them.

Discrepancies flagged

None — the numbers close.

Code and structural values are AI-generated from published tables and can be wrong or out of date. Confirm anything marked “Verify” with your local building department before you dig. Read the safety disclaimer.

Build steps

Build steps

In this order

Each phase builds on the one before, so there is always something solid to fix to.

  1. 01

    1. Layout and ledger

    Every later measurement comes off the layout, so set it out and square it before digging.

    1. Set batter boards and string the outline: 4 corners, 100 sq ft of deck.
    2. Remove siding in the ledger band, install Z-flashing, and fasten the ledger with LedgerLOK screws in two staggered rows at 16 in o.c. — dead level; the whole deck inherits any error here.
    3. Mark each beam line and the post centers along it (3 in all).
  2. 02

    2. Footings and posts

    Posts must be plumb and cut to height before a beam can go on.

    1. Dig 3 holes 14 in across to 48 in below grade (confirm the local frost depth), pour concrete, and set 4x4 post bases on the marks.
    2. When cured, cut the posts so each beam top lands where the joists need it, stand them in the bases and plumb both ways.
  3. 03

    3. Beam

    The beams have to be in place and level before any joist can span to them.

    1. Build beam B1 (10'-0") from 2 2x6s screwed together in a W pattern, crown up; set it on the post caps, level, and fasten.
  4. 04

    4. Rims and joists

    Joists carry the decking to the beams; the rims close the frame so it holds its shape.

    1. Fasten the rim joists along the outline.
    2. Lay out 7 2x8 joists at 16 in o.c. and hang them from the ledger on hangers, crown up, cut each to the rim; fasten hurricane ties at every beam.
    3. Check the frame against the plan, then apply joist tape to every joist and beam top.
  5. 05

    5. Decking

    Decking goes on once the frame is complete and square to lay against.

    1. Start the first board along the straightest edge, two screws per joist.
    2. Run the boards at a 1/8 in gap; check the remaining distance every 5 boards and adjust so the last board is full width.
    3. Trim the ends to a chalk line along every edge, and ease the edges.
  6. 06

    6. Guard

    The surface is 914 mm (36 in) above grade, so the open sides need a guard before the deck is used (OBC 9.8.8.1).

    1. Through-bolt 4x4 guard posts inside the rim, at most 6 ft apart, with a post at each corner and each side of a stair opening.
    2. Fasten 2x4 top rails flat at 36 in (914 mm) above the decking and bottom rails 3.5 in (89 mm) above it; screw vertical 2x2 balusters between them with no more than 3.5 in (89 mm) clear, so a 100 mm sphere cannot pass (OBC 9.8.8.5). Add nothing horizontal 140–900 mm above the deck that a child could climb (OBC 9.8.8.6).
  7. 07

    7. Stairs

    Stairs go last so the stringers can hang from the finished rim.

    1. Set a firm landing at grade 3'-6" out from the edge.
    2. Cut 2x12 stringers for 5 risers at 7.2 in and 4 treads at 10.5 in, and hang them from the rim across the 3'-0" opening.
    3. Fasten two decking boards per tread, then add a graspable handrail on one side (OBC 9.8.7.1 requires one on exterior stairs with more than 3 risers).

05What this plan assumes

  • Sized from the span tables for a 10 × 10 ft deck 3 ft above grade, attached to the house with a ledger.
  • Designed to the Ontario Building Code 2024, Part 9 for a deck in Ontario: its guard, footing depth and post rules apply. Joists, beams and posts are sized from the Canadian Wood Council's deck span guide (1- to 3-ply beams; 4x4 posts up to 6.5 ft, which the building department is asked to confirm); footing sizes use the US AWC DCA 6 table for reference. Confirm the sizes with your building department. 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 town isn't known, so the snow load and frost depth are not looked up: the deck is designed for Part 9's 1.9 kPa (40 psf) minimum deck load, and a town with heavy snow can need more. Tell the planner where you are building to check them.
Make it yours

Not quite your size?

Open this plan in 16Span and ask for changes in plain words, like "make it 2 ft deeper" or "add stairs on the left". The structure is checked again, and the materials and price follow.