Plumbing Rough-In Takeoff — Fittings, Valves, and Hangers

The pipe schedule tells you diameters and routes. The rough-in takeoff turns that into the hundreds of small items that actually make up most of the plumbing BOM.

Measure pipe by system

Take off supply, drainage, vent, and hot-water pipe separately, by diameter. Measure along the routing (risers vertical, branches horizontal), add 10% for waste and cut-offs, and add fixture connection stub allowances (0.5–1.0 m per fixture).

Fittings by ratio

Counting every elbow off the drawing is slow and error-prone. A ratio method is close enough for bidding:

Or count fittings per fixture group: a typical bathroom rough-in is ~12–18 supply fittings and ~8–12 drainage fittings.

Valves and specialties

Count directly: isolation valves at every fixture group and riser base, check valves at pump discharges, PRVs per pressure zone, hose bibs, floor drains, cleanouts (at every change of direction over 45° and every ~15 m of horizontal drain), water hammer arrestors at quick-closing valves.

Hangers and supports

Add riser clamps at each floor, and pipe sleeves at every wall and slab penetration (count from the routing).

Insulation

Insulate hot-water and recirculation pipe (energy), cold-water pipe in unconditioned spaces (condensation), and any pipe subject to freezing. Measure by length and diameter, matching the pipe takeoff.