FPC §604 supply sizing & §702 DWV sizing — residential & commercial
Florida Plumbing Code 2023| Fixture | Private (WSFU) | Public (WSFU) |
|---|---|---|
| Toilet (flush tank) | 2.5 | 5.0 |
| Toilet (flushometer) | 6.0 | 10.0 |
| Lavatory / bathroom sink | 1.0 | 2.0 |
| Bathtub (with shower) | 2.0 | 4.0 |
| Shower stall | 2.0 | 4.0 |
| Kitchen sink | 1.5 | 3.0 |
| Dishwasher (domestic) | 1.5 | — |
| Laundry tray | 1.5 | 3.0 |
| Washing machine | 3.0 | — |
| Hose bib (sillcock) | 2.5 | 5.0 |
| Urinal (flush tank) | — | 3.0 |
| Service sink | 3.0 | 3.0 |
| Bar sink | 1.0 | 2.0 |
| Ice maker | 0.5 | 1.0 |
| Water softener | 1.0 | — |
| Total WSFU | Min Pipe Size | Typical Use |
|---|---|---|
| Up to 3 | 1/2 inch | Single fixture branch |
| 4–6 | 3/4 inch | Small bath group |
| 7–15 | 3/4 inch | Small residence |
| 16–30 | 1 inch | Medium home |
| 31–60 | 1-1/4 inch | Large home / small commercial |
| 61–100 | 1-1/2 inch | Multi-bath commercial |
| 101–180 | 2 inch | Medium commercial |
| 181–300 | 2-1/2 inch | Large commercial |
| 301+ | 3 inch + | Large commercial / multi-family |
| Fixture | DFU Value | Trap Size |
|---|---|---|
| Toilet | 4 | 3" |
| Lavatory / sink | 1 | 1-1/4" |
| Bathtub | 2 | 1-1/2" |
| Shower stall | 2 | 2" |
| Kitchen sink | 2 | 1-1/2" |
| Dishwasher | 2 | (connects to KS) |
| Washing machine | 3 | 2" |
| Laundry tray | 2 | 1-1/2" |
| Floor drain | 2 | 2" |
| Urinal (wall hung) | 4 | 2" |
| Service sink | 3 | 3" |
| Bar / prep sink | 1 | 1-1/2" |
| Roof drain | Per GPM | — |
| Pipe Size | Max DFU (Horiz) | Max DFU (Stack) | Max DFU (Building) |
|---|---|---|---|
| 1-1/4" | 1 | 2 | — |
| 1-1/2" | 3 | 4 | — |
| 2" | 6 | 10 | — |
| 2-1/2" | 12 | 20 | — |
| 3" | 20 | 48 | 36 |
| 4" | 160 | 240 | 216 |
| 5" | 360 | 540 | 480 |
| 6" | 620 | 960 | 840 |
| Drain Pipe Size | Min Vent Size | Max Vent Length |
|---|---|---|
| 1-1/4" | 1-1/4" | 45 ft |
| 1-1/2" | 1-1/4" | 60 ft |
| 2" | 1-1/2" | 120 ft |
| 3" | 2" | 180 ft |
| 4" | 3" | 212 ft |
| 6" | 4" | 300 ft |
| Section | Topic | Key Rule |
|---|---|---|
| §604.1 | Supply sizing general | Size all supply pipe per WSFU Table 604.3 for velocity max 8 ft/sec |
| §604.3 | Fixture unit table | WSFU values by fixture type and private vs public use |
| §604.4 | Supply pipe sizing table | Pipe diameter by total WSFU demand |
| §604.6 | Velocity limits | Max 8 ft/sec in supply; max 4 ft/sec at final branch |
| §604.8 | Pipe support | Copper horizontal: 6 ft max; vertical: 10 ft max |
| §701.1 | DWV general | All drainage by gravity unless approved ejector |
| §702.1 | DFU fixture table | Fixture unit values by fixture type |
| §702.3 | Drain pipe sizing | Pipe diameter by DFU for horizontal, vertical, and building drains |
| §706.3 | Drain slope | Min 1/4" per foot for 3" and smaller; 1/8" acceptable for 4"+ with approval |
| §708.1 | Cleanout access | Required at base of each stack and each 100 ft of horizontal drain |
| §906.1 | Vent pipe sizing | Min vent by drain served; max vent length table per §906 |
| §912.1 | Wet venting | Permitted in residential — limits on fixture type and count |
| County | Commercial Notes |
|---|---|
| Miami-Dade | Requires structural engineer-stamped plans for commercial plumbing over $25K; separate MEP review from building structural; water department approval for mains >2" |
| Broward | Fire suppression and plumbing must be submitted together for new construction; grease interceptor sizing requires Health Dept sign-off for food service |
| Hillsborough | Tampa Water Dept approval required for backflow on commercial mains; permits issued through HCBCC building portal; plan review 10–14 days standard |
| Orange | Orange County requires separate plumbing plan submittal for commercial; OC Utilities must approve tap for new water service above 1" |
| Palm Beach | Commercial WH and supply pipe require licensed Mechanical and Plumbing Engineer of Record stamp for new buildings |
| Home Type | Typical WSFUs | Typical DFUs | Min Supply Main |
|---|---|---|---|
| 2BR/1BA condo | 12–16 | 14–18 | 3/4" |
| 3BR/2BA single family | 20–28 | 22–32 | 1" |
| 4BR/3BA single family | 28–40 | 30–45 | 1–1-1/4" |
| 5BR/4BA large home | 40–60 | 45–65 | 1-1/4–1-1/2" |
| Duplex (each unit) | 20–30 | 22–35 | 1" per unit |
| Small commercial (1 restroom) | 20–35 | 25–40 | 1–1-1/4" |
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Costs vary by scope, home size, and your Florida region. Use the calculator above for a Florida-specific estimate rather than a one-size-fits-all price.
Pricing depends on the size and layout of your home, the pipe materials and fixtures you choose, your Florida region and local labor rates, and permit fees. Work that is more complex or harder to access generally costs more.
In Florida, minor maintenance may be DIY, but anything beyond that generally calls for a licensed plumber, and many jobs require a permit and inspection. When a permit, or your main water or drain lines are involved, hire a Florida-licensed plumber.
It depends on the cause and your specific policy. Sudden, accidental damage is more often covered than gradual wear-and-tear or maintenance - confirm the details with your insurer.
Timelines depend on scope - many routine jobs take a few hours to a day, while larger projects run longer. Your licensed plumber can confirm after assessing your home.
Planning estimate, not a quote — confirm with a licensed Florida plumber. Confidence is qualitative: ranges reflect this page’s Florida assumptions, not a guaranteed price.
Estimates on this page are Florida-specific and reflect Fixture Unit Calculator for typical Florida homes.
From this page: Costs vary by scope, home size, and your Florida region. Use the calculator above for a Florida-specific estimate rather than a one-size-fits-all price.
Your actual cost depends on your home's condition, layout, and local labor and permit rates.
From this page: Pricing depends on the size and layout of your home, the pipe materials and fixtures you choose, your Florida region and local labor rates, and permit fees. Work that is more complex or harder to access generally costs more.
Generally raises cost: harder access, older homes, added permits and inspections, premium fixtures or materials, and emergency or after-hours work.
Generally lowers cost: easy access, bundling several items in one visit, standard fixtures, and off-peak scheduling.
Curated Florida tools and resources related to this page.
Last reviewed: July 1, 2026 (US Eastern)
Reviewed by the FL Plumbing Tools editorial team.
Sources: Florida plumbing cost research and Florida Building Code / local authority-having-jurisdiction (AHJ) permit references.
Florida reference: Estimates and guidance reflect Florida labor rates, permitting, hard water, humidity, and coastal conditions.
Updates: Reviewed periodically and updated as Florida codes, permit fees, and market rates change.