New construction plumbing in FL happens in two distinct phases: rough-in (before walls and slab are closed) and trim-out (after all construction is complete). Because FL builds on concrete slabs with no basement access, all underground drain lines must be precisely located and installed before the foundation is poured — this is permanent and cannot be moved cheaply later.
All drain and supply lines installed in the ground before the slab is poured. FL building department inspection required and must pass before concrete pour. The most critical and unforgiving phase — errors require saw-cutting the slab to repair.
After the underground inspection passes, concrete is poured over the drain lines. Underground plumbing is now permanently inaccessible without destructive saw-cutting. Any errors discovered at this stage are expensive to remedy — $3,000–8,000 or more per repair.
Supply lines (PEX) and vent pipes installed inside walls and between floors during the framing stage. A second plumbing inspection by the building department is required before drywall is installed. All pipe penetrations must be protected with fire-blocking per FL Building Code.
All visible fixtures installed after drywall and finish work is complete — toilets, faucets, shower valves, water heater, dishwasher, laundry hookups, and all appliance connections. This is the phase homeowners see and interact with daily.
Building department inspects all installed fixtures, pressure-tests the system, and verifies FL Building Code compliance. The certificate of occupancy (CO) cannot be issued until all plumbing inspections are passed and closed.
FL homes are 100% slab-on-grade. Zero access to underground plumbing after slab pour. The underground phase is permanent and unforgiving — there is no second chance.
FL's chloramine-treated municipal water and regional hard water conditions cause premature copper corrosion. PEX-A and PEX-B are now the FL standard for all supply line rough-in.
FL adopted the 2020 Florida Building Code Plumbing edition. Specifies pipe sizing, vent requirements, trap distances, fixture unit calculations, and water heater requirements statewide.
FL requires backflow preventers on all irrigation connections, pool fill lines, and any cross-connection point with the potable water supply — required in all FL new construction (FL Building Code §608).
| Material | Use | FL Pros | FL Cons | Cost |
|---|---|---|---|---|
| PEX-A | Supply lines | Flexible, chloramine-resistant, freeze-tolerant, expandable fittings | Cannot be exposed to UV (must be in-wall) | $$ |
| PEX-B | Supply lines | Less expensive, widely available, widely used in FL | Less flexible than PEX-A, crimp fittings | $ |
| CPVC | Supply lines | UV resistant, rigid, can be used above slab | Can crack in FL freeze events, less preferred | $ |
| PVC / ABS | Drain/waste/vent | FL standard for DWV systems, cost-effective, durable | None — this is the standard and preferred choice | $ |
| Copper | Supply lines | Proven 50+ year track record, rigid, accepted everywhere | FL chloramine water causes pitting over time, expensive | $$$ |
| PEX-AL-PEX | Supply lines | Less thermal expansion, good for long hot-water runs | Less common in FL, requires specific fittings | $$ |
* Cost ratings: $ = economical, $$ = mid-range, $$$ = premium. PEX-A/B recommended for FL new construction supply lines.
FL FS 553.84 and the FL Homebuilder Warranty Act protect new home buyers from defective plumbing work.
Keep all inspection reports, as-built drawings, and written warranties. FL also allows private right of action for FL Building Code violations under FS 553.84.
Every phase of new construction plumbing in FL requires a separate permit and inspection. No permit = no protection under FL Building Code.
| Phase | Permit | Who Pulls It | Inspection Trigger |
|---|---|---|---|
| Underground rough-in | ✅ Yes | Licensed plumbing contractor | Before slab pour |
| Framing rough-in (in-wall) | ✅ Yes | Licensed plumbing contractor | Before drywall |
| Gas piping | ✅ Yes (separate gas permit) | Licensed plumbing or gas contractor | Before drywall |
| Water heater | ✅ Yes (typically included) | Same plumbing contractor | At trim-out |
| Final plumbing inspection | ✅ Yes | Building department | Before CO issued |
| Irrigation backflow | ✅ Yes | Licensed contractor | Separate inspection |
| Sewer connection | ✅ Yes | Utility coordination | Before slab |
| Septic system (if applicable) | ✅ Yes (FL DOH) | Licensed septic contractor | Separate DOH process |
Check off each item as you verify with your builder or plumbing contractor. Save this list for your records.
Walk away or demand an explanation if your builder or plumbing contractor does any of the following: