Flow Pros Plumbing replaces cast iron drain and sewer pipe in St. Petersburg, FL, from a single cracked section to every line under the slab. Spot repairs usually run $800 to $5,000 and full replacements $7,000 to $30,000, quoted in writing after a camera inspection. Flow Pros replaces cast iron with new PVC and does not line pipes. Call 727-265-9639.
- FL #CFC1433820
- Serving Tampa Bay Since 2020
- Navien & Rinnai Certified
- Backflow & OSHA Certified
- Updated October 12, 2026
Cast Iron Pipe Replacement in St. Petersburg
Cast iron pipe replacement removes corroded or cracked cast iron drain and sewer lines and installs new PVC pipe in their place. In St. Petersburg, cast iron was the standard drain pipe in homes built from the 1940s into the 1970s, so it is still under the slabs of many homes across the city, from Old Northeast and Kenwood to the midcentury neighborhoods of west St. Pete. Flow Pros handles three kinds of cast iron work, all dispatched from 2770 25th St. N:
- Spot repairs. One cracked section, a broken hub joint or a failed fitting is cut out and replaced with new PVC.
- Under-slab replacement. The main building drain and branch lines under the house are replaced when the camera shows the pipe is failing along its length.
- Sewer lateral replacement. The line from the house to the city or county sewer is replaced, including work under the St. Petersburg and Pinellas County rebate programs.
Signs Your Cast Iron Pipes Are Failing
Cast iron fails from the inside: sewer gas and standing water corrode the wall, scale narrows the opening, and the bottom of the pipe can wear through in a long groove called channeling. The first signs usually show up at the fixtures, not the pipe.
- Several drains running slowly at once, or backups that return after the line is cleared.
- Gurgling from toilets or tubs when another fixture drains.
- A sewer smell inside the house with no clogged fixture to explain it.
- Damp or discolored flooring, or swollen baseboards, near a bathroom or the kitchen on a slab home.
A camera inspection confirms what is happening. It shows cracks, scale, channeling, root intrusion at joints and low spots called bellies, and the recording tells you whether a spot repair will hold or the line needs replacing. Slow drains alone can also come from an ordinary clog, which drain cleaning fixes.
Cast Iron Spot Repair vs. Full Replacement Cost
A cast iron spot repair at Flow Pros usually costs $800 to $5,000, and a full replacement usually costs $7,000 to $30,000. The camera inspection decides which one you need.
| Job | Typical price | When it fits |
|---|---|---|
| Spot repair | $800 to $5,000 | One cracked section, a broken hub joint or a failed fitting, with the rest of the line still sound on camera. |
| Full replacement | $7,000 to $30,000 | Corrosion, scale or channeling along most of the line, repeated spot repairs, or a lateral that is failing from the house to the sewer. |
Where a job falls in each range depends on four things:
- Length of pipe. How many feet of cast iron come out, and how many branch lines tie in.
- Location. Pipe under the slab costs more to reach than pipe under the yard.
- Access method. Cutting a trench through the floor, tunneling under the slab, or digging a trench outside.
- Restoration. Patching concrete, and whether tile, wood floors or a driveway sit above the pipe.
Flow Pros gives you a written quote before work begins, and financing is available.
How Flow Pros Replaces Cast Iron Pipe
A cast iron replacement follows the same steps whether it is one section or the whole house.
- Camera inspection of the line, with the recording kept for you and for any rebate application.
- Written quote that names the method, the length of pipe and what will be opened and restored.
- Permit pulled for the work, since drain and sewer replacement is permitted work.
- The cast iron is cut out and new PVC is installed at the correct slope, with cleanouts where the line needs them.
- The new line is tested, inspected and backfilled, and the floor, yard or driveway is restored.
Under a slab, the pipe is reached either through a trench cut in the floor or through a tunnel dug under the slab from outside. Outside the house, the sewer lateral is reached with an open trench. For leaks on the water side of the plumbing rather than the drains, see slab leak detection and repiping.
St. Petersburg and Pinellas County Sewer Lateral Rebates
Two local programs pay part or all of the cost of inspecting and replacing a private sewer lateral, the pipe from your house to the public sewer. Many laterals on older Pinellas homes are cast iron or clay. The rebates do not cover drain lines under the slab, and each program approves applications and pays rebates itself, first come, first served while funds last.
| Program | What it pays | Who qualifies |
|---|---|---|
| City of St. Petersburg Private Lateral Rebate | Phase 1: full rebate of inspection and rehabilitation costs. Phase 2, which the city expected to launch in October 2026: up to $5,000. Caps of $500 for the inspection and $150 per linear foot of rehabilitation. | Single-family homes on the city sewer. Phase 1 covers 13 neighborhoods. The work must be done by a plumber certified or registered with the city's Building Department. |
| Pinellas County Utilities Private Sewer Lateral Rebate | 100% of the inspection, up to $350, and 50% of repair, replacement or lining, up to $3,500. | Single-family homes connected to the Pinellas County Utilities sewer, with work done on or after October 1, 2022 by a plumber registered with the Pinellas County Contractor Licensing Board. Apply within 90 days of the inspection or permit closing. |
See also main line repair and replacement and sewer and drain service. Verify any plumbing contractor's license on the Florida DBPR license search.
- Call: 727-265-9639
- Headquarters: 2770 25th St. N, St. Petersburg, FL 33713
- Second office: 16132 Churchview Dr, Suite 209B, Lithia, FL 33547
- Hours: 24/7 Emergency Service
- License: Florida State Certified Plumbing Contractor #CFC1433820
Cast Iron Pipe Replacement FAQs
How much does cast iron pipe replacement cost in St. Petersburg?
At Flow Pros, a spot repair on a cast iron line usually costs $800 to $5,000, and a full cast iron replacement usually costs $7,000 to $30,000. The price depends on how many feet of pipe are replaced, whether the pipe runs under the slab or under the yard, and how the floor or driveway is opened and restored. You get a written quote after a camera inspection and before any work starts.
Does Flow Pros line cast iron pipes?
No. Flow Pros does not line cast iron pipes. Every repair and replacement removes the damaged cast iron and puts new PVC pipe in its place, whether that is one section or the whole line.
How long do cast iron drain pipes last?
Cast iron drain and sewer pipe is commonly expected to last 50 to 75 years. Many St. Petersburg homes built from the 1940s through the 1970s still have their original cast iron, so a lot of these lines are at or past that range. A camera inspection shows how much wall is left before you decide between a spot repair and a full replacement.
Will a rebate pay for cast iron sewer pipe replacement?
It can, for the private sewer lateral that runs from your house to the public sewer. The City of St. Petersburg and Pinellas County Utilities both run rebate programs for single-family homes, with different amounts, rules and deadlines. The rebates cover the lateral, not the drain lines under your slab, and approval and funding come from the city or county. Flow Pros does lateral replacements under both programs.
Do I have to replace all of my cast iron pipes at once?
No. If the camera shows one cracked section or a failed fitting and the rest of the pipe still has good wall thickness, a spot repair is the right job. Full replacement makes sense when the inspection shows corrosion, scale or channeling along most of the line, or when spot repairs keep coming back.
Does cast iron replacement mean breaking up my floor?
Sometimes. Pipe under a slab is reached either by cutting a trench through the floor or by tunneling under the slab from outside, and a sewer lateral is reached by digging a trench in the yard. Flow Pros explains which method fits your house, and what will be opened and restored, before the quote is signed.
Cast Iron Drains Backing Up in St. Petersburg?
Camera inspection, a written quote, and new PVC in place of the old cast iron. Owner-operated under FL #CFC1433820 since 2020.
Call 727-265-9639 Schedule Service