FL Plumbing Rough-In Calculator
Specs, checklists, FL Code reference.
Bathroom Rough-In Specs
FL Code Clearance Summary
| Fixture | Side Clearance | Front Clearance | Between Fixtures |
|---|---|---|---|
| Toilet | 15" CL to wall (18" FL preferred) | 21" min (24" FL preferred) | 30" CL to CL |
| Lavatory | 15" from any obstruction | 21" min | 30" CL to CL |
| Walk-In Shower | - | 24" in front | N/A |
| Bathtub | - | 24" one long side | N/A |
| Bidet | 15" CL to wall | 21" min | 30" CL to CL |
| Urinal | 15" CL to wall | 21" min | 30" CL to CL |
FL Code Notes - Bathroom Plumbing
FPC 2023 Table 405.3 - Clearances: Florida has adopted the IPC with FL amendments. Table 405.3 sets minimum clearances. FL additionally requires 18" from toilet centerline to side wall in all NEW construction (15" is code minimum, 18" is FL standard of practice). Front clearance of 24" is strongly recommended. Any residential bathroom remodel pulling a permit must meet current clearance standards if any fixture is relocated. Like-for-like replacement in the same location does not require clearance upgrades.
FL Shower Pan Requirements: All showers require either a pre-fab receptor, a tile-ready foam base, or a traditional lead or PVC pan liner with mortar bed. PVC liner min 40 mil, run up walls 3" above curb. Liner must be flood-tested (2" above threshold) for 24 hours before inspection. Shower drain minimum 2" IPS. Tile-ready pans must slope 1/4" per foot. FL inspectors commonly fail showers with insufficient slope.
Slab-on-Grade Rough-In (FL Specific): Most FL homes are slab-on-grade. All DWV rough-in is done BEFORE the slab is poured. Common issues: (1) all pipe penetrations must be sleeved (Sch 40 PVC sleeve 2 sizes larger); (2) toilet flange must be at or above finished floor; (3) penetration locations must match blueprint exactly; (4) underground PVC must be Sch 40 minimum (Sch 20 not permitted under slab); (5) underground copper must be sleeved in PVC.
Water Heater Rough-In in FL: (1) Overflow pan REQUIRED under ALL water heaters, pan drain to exterior; (2) expansion tank required where a backflow preventer or PRV is on the main; (3) T&P valve drain line same diameter as outlet (usually 3/4"), terminate 6"-18" above floor drain or outside, no PVC within 18" of valve outlet; (4) gas WH need earthquake straps in coastal counties, union fittings required; (5) electric WH need 240V 30-amp dedicated circuit and disconnect within 3 feet (FL amendment).
Kitchen & Utility Rough-In
Washing Machine Overflow Pan - FL Required: Required where the washer is over finished living space. Pan must be 24" x 24" minimum, 1" depth, with 3/4" drain to exterior or approved location. One of the most commonly missed items.
Dishwasher High-Loop / Air Gap - FL Rules: FL requires either a high-loop or an air gap fitting. Air gaps required where local codes/health departments specify (common in coastal counties). Drain connection must be above the trap arm of the sink drain.
Ice Maker Line Requirements: Old-style saddle valves are now generally prohibited in FL for new construction and permitted remodels. Requires a tee with 1/4" ball valve or angle stop, 1/4" OD copper/CPVC/PEX tubing, compression fitting at refrigerator. Max run 25 feet.
Pot Filler FL Code: Must have an integral shutoff at the wall, anti-siphon protection, 1/2" supply line minimum, rough-in typically 78" AFF. Pot fillers require a separate permit in most FL counties.
FL AAV Rules: AAVs (Studor vents) permitted for limited use only: island sink venting, under-cabinet remodels, utility sink additions. NOT allowed for main stack venting, toilets, or as the only vent for an entire branch. Must be accessible and 4" above trap arm.
FL Material Approvals - Supply & DWV
| Material | Supply | DWV | Underground | FL Note |
|---|---|---|---|---|
| Type L Copper | Approved | Approved | With sleeve | Standard for FL supply |
| Type M Copper | Approved | Approved | Not recommended | Thin wall, FL soils |
| PEX-A | Approved | Not for DWV | With sleeve | Most popular in new FL construction |
| PEX-B / PEX-C | Approved | Not for DWV | With sleeve | FL approved |
| CPVC | Approved | Approved | Approved | Common in FL commercial |
| PVC Sch 40 (DWV) | Not for supply | Approved | Approved | FL standard DWV material |
| ABS | Not for supply | Approved | Approved | Less common in FL |
| Cast Iron | Not for supply | Approved | Approved | Preferred for stacks (noise) |
| Polybutylene (PB) | PROHIBITED | PROHIBITED | PROHIBITED | Class action recall - never use |
| Galvanized Steel | Replacement only | Replacement only | Not recommended | Cannot use in new FL construction |
FL Inspection Checklist
Includes Pre-Rough-In, Rough-In, Cover, and Final phases, plus a list of the 15 Most Common FL Inspection Failures (interactive checklist).
DFU (Drain Fixture Unit) Reference
Required by FL Plumbing Code Table 709.1.
| Fixture | Private (DFU) | Public (DFU) | Trap Size |
|---|---|---|---|
| Toilet | 4 | 6 | Floor flange |
| Bathtub | 2 | 2 | 1-1/2" |
| Shower | 2 | 2 | 2" |
| Lavatory (sink) | 1 | 2 | 1-1/4" or 1-1/2" |
| Kitchen Sink | 2 | 4 | 1-1/2" |
| Dishwasher | 2 | 2 | Connects to K sink |
| Garbage Disposal | +2 | +2 | Add to K sink |
| Clothes Washer | 3 | 3 | 2" standpipe |
| Floor Drain | 2 | 2 | 2" |
| Laundry Tub | 2 | 2 | 1-1/2" |
| Bidet | 2 | 2 | 1-1/2" |
| Urinal | 4 | 4 | 2" |
| Mop Sink | 3 | 3 | 2" |
| Drinking Fountain | 1 | 1 | 1-1/4" |
| Food Service Sink | 2 | 2 | 1-1/2" |
Minimum Drain Pipe Size by DFU Load
| Pipe Size | Max DFU (Horizontal) | Max DFU (Vertical) | Note |
|---|---|---|---|
| 1-1/4" | 1 | 2 | Lavatory only |
| 1-1/2" | 3 | 4 | No toilet |
| 2" | 6 | 10 | No toilet on 2" horizontal |
| 3" | 20 | 48 | No toilet on 3" horizontal |
| 4" | 160 | 240 | Max for residential stack |
| 5" | 360 | 540 | Commercial |
| 6" | 620 | 960 | Commercial |
Venting Guide - What FL Allows
| Vent Type | FL Allowed? | Use Case |
|---|---|---|
| Individual Vent | Yes - Preferred | One fixture, direct to stack or roof |
| Common Vent | Yes | Two fixtures on same horizontal branch |
| Wet Vent | Yes - limited | Bath group fixtures, sized up |
| Circuit Vent | Yes | Battery of fixtures, commercial |
| Stack Vent | Yes | Top of soil stack extended through roof |
| AAV | Limited use | Islands, remodels - cannot serve main stack or toilet |
| Cheater Vent (auto vent) | Not allowed | Old style spring-loaded - not FL code |
Water Supply Sizing Guide (FL Residential)
| Supply Size | Max Fixtures | Max Length | Pressure Drop/100ft |
|---|---|---|---|
| 1/2" copper | 1-3 fixtures | 30 ft from manifold | ~10 PSI |
| 3/4" copper | 4-8 fixtures | 60 ft from main | ~4 PSI |
| 1" copper | 9-15 fixtures | 100 ft from main | ~2 PSI |
| 1/2" PEX | 1-2 fixtures | 25 ft from manifold | ~12 PSI |
| 3/4" PEX | 3-6 fixtures | 50 ft from manifold | ~5 PSI |
| 1" PEX | 7-12 fixtures | 80 ft from main | ~3 PSI |
Common Rough-In Mistakes We Fix
- Toilet drain too far from wall (wrong rough-in distance for toilet purchased)
- Missing expansion tank with PRV or backflow preventer on main
- Shower drain too shallow - liner can't seal properly, fails flood test
- Vent pipe too small for toilet (FL requires 2" minimum toilet vent)
- Horizontal drain run with wrong slope - too flat (backup) or too steep (solids strand)
- Water heater T&P valve discharge line wrong - too long, too small, or wrong material
- Washing machine standpipe wrong height - must be 18"-48" AFF in FL
- Underground copper pipe not sleeved through slab penetration
FL Rough-In Pricing Reference (2025)
| Scope | Price Range | Notes |
|---|---|---|
| Toilet rough-in | $150-$300 | Per toilet, includes flange |
| Sink rough-in (bath) | $100-$200 | Supply + drain stub-outs |
| Walk-in shower rough-in | $250-$500 | Includes pan liner if tiled |
| Tub/shower combo rough-in | $200-$400 | Access panel required |
| Kitchen sink rough-in | $150-$300 | Includes DW branch |
| Dishwasher rough-in | $100-$200 | Supply + air gap |
| Water heater rough-in | $200-$400 | Includes pan + expansion tank |
| Washing machine rough-in | $150-$300 | Includes overflow pan |
| Full bathroom (3 fixtures) | $600-$1,200 | Toilet + sink + shower |
| Full kitchen | $450-$900 | Sink + DW + disposal |
| Whole-house new construction | $3,500-$8,000 | Includes permit coordination |
| Failed inspection fix | $250-$1,000 | Depends on scope of failure |