Plumbing rough-in takeoff

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.

In Canada (3 fixtures)

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:

• 5 × 3.66 m lengths, PVC DWV pipe, 1½ in: vent for 1 toilet 1.83 m + 1 lavatory 1.22 m + vent for 1 lavatory 1.83 m + 1 tub/shower 1.52 m + vent for 1 tub/shower 1.83 m + vent header 6.10 m = 14.33 m, + 10% for cuts → 5 × 3.66 m.
• 3 × 3.66 m lengths, PVC DWV pipe, 3 in: 1 toilet 1.22 m + branch 6.10 m = 7.32 m, + 10% for cuts → 3 × 3.66 m.
• 26 fittings, DWV fittings, 1½ in (PVC or ABS): Allowance: the trap or bend, tees and elbows at each fixture (3–4), 3 per vent, a wye or combo per fixture on the branch, long sweeps, and a coupling between lengths.
• 10 fittings, DWV fittings, 3 in (PVC or ABS): Allowance: the trap or bend, tees and elbows at each fixture (3–4), 3 per vent, a wye or combo per fixture on the branch, long sweeps, and a coupling between lengths.
• 2 473 mL can sets, PVC primer and cement (pint set): About 128 joint-equivalents (a 3 in joint takes about 2½ times the cement of a 1½ in one); a 473 mL can does about 90 of the small ones.
• 1 × 30.48 m coil, PEX-A tubing, ½ in: 5 branches × 1.83 m = 9.14 m, + 10% → 1 × 30.48 m coil. ½ in to every fixture (the codes allow ⅜ in for some — lavatories and toilets — but ½ in covers all).

1. Pull the plumbing permit (plumbing subcode, filed by the master plumber) and post it on site.
2. Lay out from the fixture spec sheets and the finished wall and floor lines: drain centers, trap arm heights and supply stubs (the rough-in card on the drawing has typical heights).
3. Bore and notch within the framing code’s limits — ask the framer or engineer before cutting any joist, beam or truss — and put nail plates where pipe sits within 1¼″ of the face.
4. Set the closet flange, tub and shower drains and the traps, then run the drain branch to the stack or main at ¼″ per foot — wyes and long sweeps for horizontal turns, sanitary tees only from horizontal into vertical.
5. Run the vents: every trap arm within its limit, every vent off the top of its trap arm and up at least 6″ above the flood rim before it turns flat, the header into the existing vent stack.
6. Run the water lines: trunk and branches in PEX-A, hot on the left, strapped at the code spacing; stub out and cap every outlet.
7. Test the drains and vents once the solvent-welded joints have set: filled with water to the top, at least a 10 ft head, for 15 minutes, or air at 5 psi for 15 minutes — plastic DWV only where the pipe maker allows air (IPC 312).
8. Test the water lines: at least the working pressure with water, or air at 50 psi on metal pipe — not on plastic (IPC 312.5).
9. Rough-in inspection with the tests holding, the caps on and the nail plates in — before insulation and drywall.
10. After drywall: stops, traps and fixtures at trim-out, then the final inspection.

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

Mistakes that cost a callback or a second trip

• Roughing in before the fixtures are picked: Toilets come in 10″, 12″ and 14″ rough-ins, tub drains go left or right, and wall-mount faucets need their own stubs. Get the spec sheets first.
• A sanitary tee on its back: Sanitary tees only turn flow from horizontal into vertical. On a horizontal drain they choke the flow and fail inspection — use a wye or a combo.
• A vent below the trap weir: A vent that leaves the trap arm below the weir, or a trap arm longer than the table allows, siphons the trap dry and lets sewer gas in.
• Air-testing plastic drains: Many PVC and ABS makers forbid testing their pipe with compressed air: a fitting that lets go can shatter. Water-test unless the maker and the inspector allow air.
• No nail plates: A drywall screw through a drain or a water line shows up months later as a stain on the ceiling. Plate every pipe within 1¼″ of the face.

What the calculator assumes

• Code: the National Standard Plumbing Code (NSPC 2021), New Jersey’s plumbing subcode. New Jersey enforces the National Standard Plumbing Code (NSPC 2021, N.J.A.C. 5:23-3.15). These sizes use the IPC tables as a cross-check; the NSPC’s tables differ in places — check each size against it. Confirm with your building department.
• Fixture units (IPC Table 709.1): bathroom group 5 (1.6 gpf toilet), toilet 3, lavatory 1 (1¼″ trap), tub or shower 2 (1½″), kitchen sink 2 with or without a dishwasher, dishwasher alone 2, washer 2 (2″), laundry tub 2, sink 2, floor drain 2 (an emergency floor drain 0).
• Horizontal branches (IPC Table 710.1(2)): 1½″ 3 DFU, 2″ 6, 3″ 20, 4″ 160; stacks of three branch intervals or fewer: 2″ 10, 3″ 48, 4″ 240. Building drains at ¼″ per foot (2%) (Table 710.1(1)): 2″ 21, 3″ 42, 4″ 216. Any drain a toilet uses: 3″ minimum. 2½″ is skipped: stores rarely stock it.
• Trap arms (IPC Table 909.1): 1¼″ 5′, 1½″ 6′, 2″ 8′, 3″ 12′, 4″ 16′.
• Vents: at least half the drain they serve and 1¼″ minimum (bought as 1½″); a 3″ vent through the roof for a new stack (cold climates require it so frost can’t close it).
• Slope: ¼″ per foot (2%) on small drains (IPC Table 704.1).
• Water: fixture units per fixture (IRC P2903.6): toilet 2.2, lavatory 0.7, tub or shower 1.4, kitchen sink 1.4, dishwasher 1.4, washer 1.4, laundry tub 1.4, hose bib 2.5 (1.0 each after the first); a full bath 3.6, half bath 2.6, kitchen or laundry pair 2.5. Peak flow on Hunter’s curve (IPC Appendix E); trunks ¾″ minimum, sized to 8 ft/s (5 ft/s hot in copper, UPC 610.12).
• Allowances (typical): fixture drains 4–5 ft (a washer 7 ft with its standpipe), a 6 ft vent per fixture, 6 ft per branch to a fixture, 10 ft manifold feeds, +10% on every pipe for cuts; PEX in 100′ and 300′ coils.
• Hangers: plastic DWV every 4 ft, cast iron every 5 ft, PEX every 32″, copper every 6 ft, CPVC every 3 ft (typical of IPC Table 308.5 and UPC Table 313.3).
• Gas piping for a range, dryer or water heater isn’t on this Sheet: the licensed gas fitter sizes and tests it.

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.

• Sized with the IPC tables: Code here: the National Standard Plumbing Code (NSPC 2021), New Jersey’s plumbing subcode. Fixture units and trap sizes from IPC Table 709.1; branches and stacks from IPC Table 710.1(2), the building drain from 710.1(1); trap arms from Table 909.1. New Jersey enforces the National Standard Plumbing Code (NSPC 2021, N.J.A.C. 5:23-3.15). These sizes use the IPC tables as a cross-check; the NSPC’s tables differ in places — check each size against it. Confirm with your building department.
• License and permit: New Jersey: plumbing is done by a master plumber licensed by the NJ State Board of Examiners of Master Plumbers, or by workers under one; the master plumber’s license number and seal go on the plumbing subcode permit application at the town’s construction office (N.J.A.C. 5:23-2.15). Inspections: rough-in with the tests holding, before the walls close; final once the fixtures are in.
• Tests the inspector watches: Drains and vents: filled with water to the top, at least a 10 ft head, for 15 minutes, or air at 5 psi for 15 minutes — plastic DWV only where the pipe maker allows air (IPC 312). Water lines: at least the working pressure with water, or air at 50 psi on metal pipe — not on plastic (IPC 312.5). Final inspection with the fixtures set and working.
• Sized with the NPC tables: Code here: the Ontario Building Code (Part 7, Plumbing). Fixture units and trap sizes from OBC 7.4.9.3; branches, stacks and building drains from OBC 7.4.10.6; vents from OBC 7.5.7; trap arms from OBC 7.5.6.3. Confirm with your building department.

What materials do I need to rough in plumbing?

For the worked example, a 3 fixtures, the Sheet counts 22 lines with waste included, starting with pVC DWV pipe, 1½ in (6 × 10′ lengths), pVC DWV pipe, 3 in (3 × 10′ lengths), dWV fittings, 1½ in (PVC or ABS) (27 fittings), dWV fittings, 3 in (PVC or ABS) (10 fittings). Each line's math is in the table above. Put in your own sizes in the plumbing calculator and every line is counted again.

How long does it take to rough in plumbing, and can I do it myself?

About 15 to 22 hours for the worked example, in 10 steps. StudSheet stamps it PRO JOB: hire this out (pros get the full Sheet).

What tools do I need to rough in plumbing?

20 in all. The must-haves start with tape measure (25 ft), carpenter's pencil, 4-ft level, torpedo level, cordless drill/driver, right-angle drill. On the Sheet you mark each one as owned, to buy or to rent.

Stuck while you rough in plumbing? Ask in the Plumbing rough-in group of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

• Plumbing for contractors: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
• Water heater replacement (Gas water heater, 4 people): For plumbers: tank or tankless, venting, expansion tank, relief line, connections and the permit.
• Replace a toilet (Toilet, 12″ rough-in): Measure the rough-in, pick a toilet that fits, and swap it with a new seal, bolts and supply line — plus what to do about a broken flange.
• Replace a bathroom vanity (30″ vanity): A vanity that fits the space and the pipes, its top and faucet, new supply lines, trap, shims and sealant — swapped in an afternoon.
• Replace a faucet (Kitchen faucet): A kitchen or bathroom faucet that fits your sink’s holes, new supply lines, the right sealant, and a leak check — or a cartridge for a drip.
• All 45 Sheets, across 16 trades.
• Code reference: frost depths, guard heights, stairs, retaining walls.