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StudSheet Sheets Decks, fences & railings · Sheet S-13

Deck calculator

16′ × 12′ deck: 3 footings, 13 joists (2×8 at 16″ o.c.), a 2-2×10 beam and 28 deck boards, every hanger and screw counted. Footings, posts, beams, joists and decking for a deck, or a balcony on posts, with the railing it needs.

Free, no account needed. Type your own sizes and every line is counted again.

Worked example · feet and inches (New Jersey) or metric (Ontario)

Sheet S-13 · Deck or balcony

16′ × 12′ deck

DIY OK
FRAMING PLAN2×8 joists at 16″ o.c., beam 2-2×10HOUSESTAIRS16′12′7′SECTIONthrough the beam, not to scale acrossfrost line36″36″3′123456789
Framing plan + section
Deck
192sq ft · 16′ × 12′
Footings
319″ × 36″ deep
Joists
132×8 at 16″ o.c.
Beam
2-2×103 posts, 7′ apart

Tools you need

  • Tape measure (25 ft)
  • Mason's line + stakes
  • Chalk line
  • 4-ft level
  • Speed square
  • Framing square

29 tools on the Sheet, each marked own, buy or rent

What to buy 22 lines, each with its math
BuyItemHow we got this
17 bagsConcrete mix, 80 lb80 lb bags3 footings: a pad 19″ across × 6″ thick at 36″ deep, then a 12″ pier up to 2″ above the ground = 3.08 cu ft each, +10% = 10.16 cu ft; 80 lb bag ≈ 0.6 cu ft (Quikrete).
3 tubesConcrete form tube12″ × 4′One per pier, cut to 32″ (from the pad to 2″ above the ground).
3 postsPressure-treated 6×6 post6×6 × 8′3 posts, about 1′ 4-1/2″ from the pier to the beam: deck 3′ − decking − joist − beam − 2″ of pier. Cut each one to the string line, not to a number.
3 basesPost base or anchor6×6 standoff, galvanizedOne per post: holds it on the pier and off the concrete (IRC R507.4.1).
3 boltsAnchor bolt ⅝″ with nut and washer⅝″, J-bolt or wedge anchorOne per post base, set in the wet concrete (or drilled in later) per the base’s label.
3 capsPost-to-beam connector (post cap)for 6×6 and a 2-ply beamTies the beam to each post (IRC R507.8).
2 boardsPressure-treated 2×102×10 × 16′Beam 2-2×10, 16′ long: 2 plies. Posts 7′ apart, 12″ in from each end; this beam spans up to 7′ 4″ with 10′ 9″ joists (the 12 ft column (IRC Table R507.5(1))).
13 boardsPressure-treated 2×82×8 × 12′13 joists 16″ on center across 16′ (12 spaces + 1), each 11′ 9″ long. 2×8 spans 10′ 9″ with a 12″ overhang (southern pine, 16″ o.c.).
1 boardPressure-treated 2×82×8 × 16′Rim joist across the joist ends, 16′ long, 3 screws into each joist end.
1 boardPressure-treated 2×82×8 × 16′Ledger 16′ long, 2×8: at least 2×8 and as deep as the joists (IRC R507.9.1).
1 boardPressure-treated 2×82×8 × 16′12 blocks of 1′ 2-1/2″ between the joists over the beam: they keep the joists from rolling (DCA 6). Cut 12 × 1′ 2-1/2″ (13 a board) from 16′ boards.
13 hangersJoist hangersfor 2×8, G185 or stainlessOne per joist at the ledger. At least 60% of the joist’s depth; every hole nailed.
13 tiesHurricane ties (joist to beam)galvanizedOne per joist where it crosses the beam (at least 100 lb up and sideways, DCA 6).
4 tiesDeck tension tie, 1,500 lb (for example Simpson DTT2Z)1,500 lb ratedLateral load: two places within 24″ of the deck’s ends (IRC R507.9.2), each a tie on a deck joist and one on a house floor joist inside, joined through the band joist.
2 rodsThreaded rod ½″ × 3 ft with nuts and washersOne per lateral-load connection, through the ledger and band joist.
14 screwsLag screws ½″ with washers (hot-dip galvanized)½″ × 4″ + washerEvery 15″ along 16′ for a 10′ 9″ joist span (IRC Table R507.9.1.3(1)), staggered top and bottom, 2″ from the edges.
2 piecesZ-flashing, 10 ftOver the top of the ledger, 6″ laps, siding lapped over it (IRC R507.2.4).
1 rollSelf-adhered flashing tape, 6″ × 75 ftBehind the ledger and over its top: two strips 16′ long, plus the bolt holes.
≈364 (4 boxes of 100)Connector fastenershanger nails or connector screwsAbout 10 per hanger and tie and 12 per post base and cap — the size on each connector’s label, not deck screws.
≈183 (2 boxes of 100)Coated deck screws3″ coated3 per joist end into the rim, 2 per block end, and the beam’s plies in two rows every 16″ (10d nails work too).
28 boards5/4×6 treated deck board5/4×6 × 16′26 rows of 5-1/2″ boards with 1/8″ gaps across 12′ = 26 boards, +5% for culls and miscuts.
≈676 screws (7 boxes of 100)Coated deck screws2½″ coated2 per board at every joist (DCA 6): ≈338 crossings.
Decks, fences & railings · Sheet S-13 · 01What to buy (16′ × 12′ deck)

What to buy (16′ × 12′ deck)

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

BuyMaterialHow StudSheet counts itWhat it is for
17 bagsConcrete mix, 80 lb (80 lb bags)3 footings: a pad 19″ across × 6″ thick at 36″ deep, then a 12″ pier up to 2″ above the ground = 3.08 cu ft each, +10% = 10.16 cu ft; 80 lb bag ≈ 0.6 cu ft (Quikrete).About 0.6 cu ft per bag.
3 tubesConcrete form tube (12″ × 4′)One per pier, cut to 32″ (from the pad to 2″ above the ground).Cardboard tube that forms a round footing or pier; cut to length with a handsaw.
3 postsPressure-treated 6×6 post (6×6 × 8′)3 posts, about 1′ 4-1/2″ from the pier to the beam: deck 3′ − decking − joist − beam − 2″ of pier. Cut each one to the string line, not to a number.Heavy post for gates, tall fences and porch or deck posts. Buy it rated for ground contact if it goes in the ground.
3 basesPost base or anchor (6×6 standoff, galvanized)One per post: holds it on the pier and off the concrete (IRC R507.4.1).Galvanized base set in or bolted to the pier that holds the post off the concrete. Use what your plans or the post’s load call for.
3 boltsAnchor bolt ⅝″ with nut and washer (⅝″, J-bolt or wedge anchor)One per post base, set in the wet concrete (or drilled in later) per the base’s label.Holds the post base to the footing: a J-bolt set in the wet concrete or a wedge anchor drilled in later.
3 capsPost-to-beam connector (post cap) (for 6×6 and a 2-ply beam)Ties the beam to each post (IRC R507.8).Galvanized cap that ties the beam to the top of the post, sized for the post and the beam’s plies.
2 boardsPressure-treated 2×10 (2×10 × 16′)Beam 2-2×10, 16′ long: 2 plies. Posts 7′ apart, 12″ in from each end; this beam spans up to 7′ 4″ with 10′ 9″ joists (the 12 ft column (IRC Table R507.5(1))).Joists, beams and ledger, actually 1½″ × 9¼″.
13 boardsPressure-treated 2×8 (2×8 × 12′)13 joists 16″ on center across 16′ (12 spaces + 1), each 11′ 9″ long. 2×8 spans 10′ 9″ with a 12″ overhang (southern pine, 16″ o.c.).Joists, ledger, rim and blocking, actually 1½″ × 7¼″. Rated for ground contact or above ground — the tag says which.
1 boardPressure-treated 2×8 (2×8 × 16′)Rim joist across the joist ends, 16′ long, 3 screws into each joist end.Joists, ledger, rim and blocking, actually 1½″ × 7¼″. Rated for ground contact or above ground — the tag says which.
1 boardPressure-treated 2×8 (2×8 × 16′)Ledger 16′ long, 2×8: at least 2×8 and as deep as the joists (IRC R507.9.1).Joists, ledger, rim and blocking, actually 1½″ × 7¼″. Rated for ground contact or above ground — the tag says which.
1 boardPressure-treated 2×8 (2×8 × 16′)12 blocks of 1′ 2-1/2″ between the joists over the beam: they keep the joists from rolling (DCA 6). Cut 12 × 1′ 2-1/2″ (13 a board) from 16′ boards.Joists, ledger, rim and blocking, actually 1½″ × 7¼″. Rated for ground contact or above ground — the tag says which.
13 hangersJoist hangers (for 2×8, G185 or stainless)One per joist at the ledger. At least 60% of the joist’s depth; every hole nailed.Galvanized (G185) or stainless brackets that hold each joist on the ledger or beam. Sized to the joist; fill every nail hole.
13 tiesHurricane ties (joist to beam) (galvanized)One per joist where it crosses the beam (at least 100 lb up and sideways, DCA 6).Small galvanized ties that hold each joist down on the beam and keep it from sliding.
4 tiesDeck tension tie, 1,500 lb (for example Simpson DTT2Z) (1,500 lb rated)Lateral load: two places within 24″ of the deck’s ends (IRC R507.9.2), each a tie on a deck joist and one on a house floor joist inside, joined through the band joist.Hold-down that ties the deck’s joists to the house’s floor framing so the deck can’t pull away.
2 rodsThreaded rod ½″ × 3 ft with nuts and washersOne per lateral-load connection, through the ledger and band joist.Joins the tension tie on the deck joist to the one on the house’s floor joist, through the band joist.
14 screwsLag screws ½″ with washers (hot-dip galvanized) (½″ × 4″ + washer)Every 15″ along 16′ for a 10′ 9″ joist span (IRC Table R507.9.1.3(1)), staggered top and bottom, 2″ from the edges.Fasten the ledger to the house’s band joist. Long enough that the tip passes through the band joist.
2 piecesZ-flashing, 10 ftOver the top of the ledger, 6″ laps, siding lapped over it (IRC R507.2.4).Metal or vinyl cap over the top of the ledger: siding laps over it, water drips off in front of the ledger.
1 rollSelf-adhered flashing tape, 6″ × 75 ftBehind the ledger and over its top: two strips 16′ long, plus the bolt holes.Rubberized tape that seals the wall behind the ledger and around every bolt hole.
≈364 (4 boxes of 100)Connector fasteners (hanger nails or connector screws)About 10 per hanger and tie and 12 per post base and cap — the size on each connector’s label, not deck screws.Use exactly what the connector maker specifies.
≈183 (2 boxes of 100)Coated deck screws (3″ coated)3 per joist end into the rim, 2 per block end, and the beam’s plies in two rows every 16″ (10d nails work too).Exterior-rated screws for treads and risers.
28 boards5/4×6 treated deck board (5/4×6 × 16′)26 rows of 5-1/2″ boards with 1/8″ gaps across 12′ = 26 boards, +5% for culls and miscuts.Tread boards, 1″ thick × 5½″ wide.
≈676 screws (7 boxes of 100)Coated deck screws (2½″ coated)2 per board at every joist (DCA 6): ≈338 crossings.Exterior-rated screws for treads and risers.

In Canada (4.88 m × 3.66 m deck)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

  • 17 bags, Concrete mix, 30 kg: 2 footings: a pad 483 mm across × 152 mm thick at 1.20 m deep, then a 305 mm pier up to 51 mm above the ground = 0.11 m³ each, +10% = 0.24 m³; 30 kg bag ≈ 0.014 m³ (Sakrete).
  • 2 tubes, Concrete form tube: One per pier, cut to 1.10 m (from the pad to 51 mm above the ground).
  • 2 posts, Pressure-treated 6×6 post: 2 posts, about 368 mm from the pier to the beam: deck 914 mm − decking − joist − beam − 51 mm of pier. Cut each one to the string line, not to a number.
  • 2 bases, Post base or anchor: One per post: holds it on the pier and off the concrete.
  • 2 bolts, Anchor bolt 16 mm with nut and washer: One per post base, set in the wet concrete (or drilled in later) per the base’s label.
  • 2 caps, Post-to-beam connector (post cap): Ties the beam to each post; a 3-ply beam always sits in a post cap.
Decks, fences & railings · Sheet S-13 · 02The steps, in order

The steps, in order

  1. Get the construction permit from your town’s construction office: bring a plan like this Sheet’s. Most inspect the footing holes, the framing and the finished deck.
  2. Call 811 (NJ One Call) at least 3 full business days ahead and wait for the utility markings.
  3. Mark the ledger line: the deck boards land 1–2″ below the door sill. Cut the siding away, and tape the wall behind the ledger with flashing tape.
  4. Fasten the ledger to the band joist with ½″ lag screws, staggered top and bottom; Z-flashing over the top, siding back down over the flashing. Never into brick, stone or a cantilevered floor.
  5. Lay out the posts with string lines from the ledger and batter boards: square the corners until the diagonals match within ¼″.
  6. Dig 3 footing holes 19″ across and 36″ deep, down to undisturbed soil below the frost line.
  7. Footing inspection: most towns check the holes before you pour.
  8. Pour each footing: the 19″ pad, then the 12″ form tube to 2″ above the ground; set the post-base anchor in the wet concrete, lined up with the string.
  9. Stand the posts in their bases and brace them plumb. Mark the beam height level from the ledger, cut the posts, and set the beam on post caps (plies screwed in two rows every 16″).
  10. Hang the joists 16″ on center, crown up: hangers at the ledger, every hole nailed, hurricane ties at the beam and blocking between the joists over it.
  11. Fasten the rim across the joist ends (3 screws per joist); check the frame square and level.
  12. Install the lateral-load ties: two connections within 24″ of the deck’s ends, through the band joist to the house’s floor joists.
  13. Framing inspection before the decking goes on.
  14. Lay the deck boards across the joists, ⅛″ gaps, 2 screws at every joist; every board end on a joist, joints staggered.
  15. Build the stairs with the Deck stairs Sheet (3′ rise).
  16. Install the guards before anyone uses the deck: about 37′, 36″ tall — the Railings and guards Sheet counts them.
  17. Final inspection.
Decks, fences & railings · Sheet S-13 · 03Tools (29)

Tools (29)

Must-have tools first, then the ones that help and the ones to rent for the day.

ToolNeedWhy
Tape measure (25 ft)Must haveThe red boxes every 16″ on the blade are stud spacing.
Long tape (100 ft)Good to haveLayout and checking the diagonals
Mason's line + stakesMust haveLines up the posts and squares the deck
Chalk lineMust haveSnaps a long straight line on floors, subfloors and ceilings.
4-ft levelMust haveChecks plumb and level over a long span.
Speed squareMust haveTriangle square for marking square and angled cuts on lumber.
Framing squareMust haveBig steel L-square. With stair gauges it lays out stair stringers.
Carpenter's pencilMust haveFlat, doesn't roll away, marks rough lumber.
Post-hole diggerMust haveFooting holes
Power augerRentMany holes, or clay: rent a two-person auger
Digging barGood to haveRocks and roots in the holes
Round-point shovelMust haveDigs.
Mixing tub + hoeMust haveMixes bagged concrete by hand.
WheelbarrowMust haveMoves gravel, soil and block.
Post levelGood to havePlumbs the posts both ways at once
Circular sawMust haveHandheld power saw for lumber and sheet goods.
Miter sawGood to haveSquare, clean board ends
Cordless drill/driverMust haveDrills holes, drives screws, mixes small batches.
Impact driverMust haveDeck screws and structural screws
Socket and ratchet setMust haveLag screws and bolts
Framing hammerMust haveHanger and tie nails
Clamps (2)Must haveHolds beam plies and joists while you fasten
Auger bit setGood to haveClean ½″ holes through the ledger and band joist
Deck board straightenerGood to havePulls bowed boards straight
SawhorsesMust haveCutting support.
Step ladder (6 ft)Must haveReaches 8-ft ceilings safely.
Safety glassesMust haveEvery cut, every nail, every time.
Hearing protectionMust haveSaws and nailers are loud enough to damage hearing.
Work glovesMust haveTack strip, block and lumber shred hands.
Decks, fences & railings · Sheet S-13 · 04Mistakes and how the math works

Mistakes and how the math works

Mistakes that cost a callback or a second trip

  • No flashing over the ledger: Water gets behind the ledger and rots the house’s band joist — the most common reason decks pull off houses. Tape behind it, Z-flashing over it, siding over that.
  • Ledger on brick, stone or a cantilevered floor: A ledger must bolt to the house’s band joist. On veneer, or where the floor joists overhang the foundation, build the deck freestanding instead.
  • Footings too shallow: Above the frost line they heave every winter; within 5 ft of the house they must reach the house footing’s depth. Dig to undisturbed soil.
  • Deck screws in the hangers: Hangers and ties hold only with the nails or structural screws on their label, in every hole.
  • Board ends between joists: Every board end lands on a joist. Where two ends meet, double the joist so each end gets a full bite.

What the calculator assumes

  • Joists: DCA 6 Table 2 (American Wood Council), the 2018 IRC Table R507.6 values (the 2021 IRC keeps them for southern pine): 40 psf live + 10 psf dead load, No. 2, wet service. Overhangs within the table’s limit and ¼ of the span.
  • Beams: IRC 2021 Table R507.5(1), 40 psf live load, read at the next joist-span column up (no interpolation); posts 12″ in from the beam’s ends (a beam may overhang ¼ of its span).
  • Posts: 6×6, up to 14′ from the footing to the beam (IRC Table R507.4); post bases and post caps (R507.4.1, R507.8).
  • Footings: IRC Table R507.3.1 for 1,500 psf soil (the presumptive value for clay), at least 12″ below undisturbed ground and below the frost line (R507.3).
  • Ledger: 2×8 or deeper on the house’s band joist, never on veneer; ½″ fasteners staggered in two rows at the spacing of IRC Table R507.9.1.3(1) for sheathing up to ½″ (thicker sheathing: bolts with stacked washers, closer); flashed (R703.4).
  • Lateral load: two 1,500 lb tension ties within 24″ of each end of the deck (IRC R507.9.2); or four of 750 lb.
  • Guards on open sides more than 30″ above the ground: 36″ tall, openings under 4″ (IRC R312; R321 in the 2024 IRC).
  • Fasteners hot-dip galvanized (ASTM A153) or stainless; connectors G185 or stainless (IRC R507.2.3).
  • Decking: 5/4 boards on joists up to 16″ (12″ diagonal), 2× boards up to 24″ (IRC R507.7); composite per the maker (16″ typical, 12″ diagonal). 2 fasteners per board at every joist; ⅛″ gaps for wood.
  • Concrete: 80 lb bag ≈ 0.6 cu ft (Quikrete); a 12″ pier on a pad the table’s size; +10% for spills.
  • Hangers, ties and post bases from one maker, with the nails and screws on their labels. Board waste +5%.
Decks, fences & railings · Sheet S-13 · 05Code, permits and safety

Code, permits and safety

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the code reference has more. Always confirm with your building department.

  • Expect a construction permit: Decks usually need a construction permit in New Jersey, with footing, framing and final inspections. Ask your town’s construction office before you build.
  • Frost depth: Footings go below the frost line: 36″ in Mercer/Middlesex and north, 30″ south.
  • Call 811 first — it’s the law: In New Jersey, call 811 (NJ One Call) at least 3 full business days before digging. Free. Wait for the utility markings.
  • Guards required: Open sides more than 30″ above the ground need a guard 36″ tall with openings under 4″ (IRC R312; R321 in the 2024 IRC); some towns ask 42″. About 37′ of guard on this deck (three open sides, less 36″ per stair): the Railings and guards Sheet counts the posts, rails and balusters.
  • Stairs: one run: Each set of steps comes down 3′: the Deck stairs Sheet lays out the stringers, treads, landing and handrail for that rise.
  • Permit likely needed: Canadian municipalities usually need a building permit for a deck more than about 600 mm above the ground, and many also for any attached deck, one serving an entrance or one over 10 m² (Carleton Place, Ontario, for example). This one is 4.88 m × 3.66 m, 914 mm up, attached. Confirm with your building department.
  • Click Before You Dig: Before you dig, request a free utility locate from Ontario Dig Authority (ontariodigauthority.ca) at least 5 business days ahead, and wait for the markings.
Decks, fences & railings · Sheet S-13 · 06Questions

Questions

What materials do I need to build a deck?

For the worked example, a 16′ × 12′ deck, the Sheet counts 22 lines with waste included, starting with concrete mix, 80 lb (17 bags), concrete form tube (3 tubes), pressure-treated 6×6 post (3 posts), post base or anchor (3 bases). Each line's math is in the table above. Put in your own sizes in the deck calculator and every line is counted again.

How long does it take to build a deck, and can I do it myself?

About 41 to 63 hours for the worked example, in 17 steps. StudSheet stamps it DIY OK: you can do this.

What tools do I need to build a deck?

29 in all. The must-haves start with tape measure (25 ft), mason's line + stakes, chalk line, 4-ft level, speed square, framing square. On the Sheet you mark each one as owned, to buy or to rent.

Decks, fences & railings · Sheet S-13 · 07Ask about it

Ask about it

Stuck while you build a deck? Ask in the Decks group of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

Decks, fences & railings · Sheet S-13 · 08More decks, fences & railings Sheets

More decks, fences & railings Sheets

  • Decks and fences for contractors: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
  • Build deck or porch stairs (Stairs for a 3′ rise): Lay out and cut stringers, treads, risers and the landing — to code.
  • Railings and guards (12′ wood railing): Wood, aluminum, steel, glass or cable railings for decks, balconies, porches and stairs: posts, panels, hardware and the height rules.
  • Fence (100′ wood fence, 6′ tall): Posts, rails, pickets or panels, concrete and gate hardware for a wood, vinyl or aluminum fence.
  • Build a raised garden bed (8′ × 4′ raised bed): Boards cut from the fewest pieces, corner posts, screws, a liner against weeds or gophers, and the soil by the bag or by the yard.
  • All 45 Sheets, across 16 trades.
  • Code reference: frost depths, guard heights, stairs, retaining walls.

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