Toilet Rough-In Distance
Toilet rough-in distance is measured from the finished wall to the center of the closet flange (drain) — NOT the toilet-to-wall gap. Standard: 12". Older FL homes may have 10" or 14". When measuring to a stud, add 0.5" for tile, 4" for typical stud wall.
Toilet Rough-In Standards
| Rough-In | Common In | Toilet Availability | Notes |
|---|---|---|---|
| 10" | Pre-1960s homes | Limited selection | Older FL plumbing |
| 12" | All eras | Full selection | Standard — widest choice |
| 14" | Some older FL | Good selection | Less common today |
Before toilet replacement, always measure existing rough-in. A 12" toilet CANNOT be used with a 10" rough-in (it will hit the wall). A 10" toilet can sometimes work with a 12" rough-in using an offset flange.
Supply and Drain Quick Reference
| Fixture | Cold Supply | Hot Supply | Drain CL |
|---|---|---|---|
| Toilet | 6–8" from floor, left | N/A | 12" from wall (std) |
| Lav sink | 20" from floor, 4" R of CL | 20" from floor, 4" L of CL | 18–20" from floor |
| Kitchen sink | Under sink box | Under sink box | 15–17" from floor |
| Shower | Valve center | Valve center | 2" trap, floor level |
| Tub/shower | 28–32" from floor | 28–32" from floor | 6" from end wall |
| Dishwasher | Under sink | N/A | Air gap at sink |
| Washing machine | 48" from floor, L | 48" from floor, R | 34–36" standpipe ht |
| Water heater | Cold: right side | Hot: left side | Floor drain nearby |
| Hose bib | 24" from grade (exterior) | N/A | N/A |
FPC Key Rough-In References
- FPC 405.3.1 Toilet location: Min 15" from centerline to any side wall/partition/cabinet (both sides). ADA: min 18" transfer side.
- FPC 405.3.2 Toilet clearance: Min 21" in front. ADA requires 60" turning radius or 30"×48" clear floor space.
- FPC 412.2 Shower receptors: Floor slopes to drain at 1/4" per foot min. Curb height 2" min. Threshold max 1/2" for accessibility.
- FPC 424.6 Grab bar blocking: FL requires blocking/solid backing in shower/tub of new residential construction (FBC 11-4.23.4). 2×8 blocking between studs.
- FPC 603.2 Water heater location: Gas WH in garage requires 18" min elevation of ignition source above floor. Drip pan required in conditioned space or above finished area.
ADA (ADA-ABA / FBC Ch. 11)
- Lavatories (FBC 1109.2): Rim height max 34"; knee clearance 27"h × 30"w × 19"d; clear floor 30"×48"; insulated supply/drain.
- Water closets (FBC 1109.4): Height 17"–19" to seat; 60" clear floor side approach or 66"×56" front; flush control on open side.
- Shower stalls (FBC 1109.6): 36"×36" transfer or 30"×60" roll-in; seat for transfer-type; controls 15"–48" AFF; hand shower on 60" min hose.
- Bathtubs (FBC 1109.5): Foot controls at 60" AFF; head controls 60" AFF max 15" from foot wall; grab bars 24" front, 12" back, side wall full length.
Rough-In Compliance Checklist
Toilet centerline ≥15" from side walls (FPC 405.3.1; ADA 18" transfer); min 21" clear in front (30" ADA); shower floor slopes 1/4" per foot (FPC 412.2); grab bar blocking installed (FBC 11-4.23.4, 2×8 at 33"–36" AFF); WH drip pan where applicable (FPC 501.6); lavatory drain CL 16"–18" from side wall (FPC 405.4); shower valve anti-scald (ASSE 1016/1070, max 120°F); supply stub-outs match fixture spec (8" cold-to-hot on center); all rough-in inspected before walls closed.