Cast Iron Pipes Florida Homes
The drain line under the slab is the most expensive thing you can't see
Cast iron drain pipes are common in Florida homes built before the mid-1970s, and many are now failing from the inside, which is why a camera inspection of the drain line belongs in the inspection period on any older house. On a Florida single-family home with a typical value of $396,809 in Zillow's home value index, a full under-slab repipe is one of the few repairs large enough to change your offer.
- Typical home value
- $375K Florida, Zillow, September 2026
- Past year
- −0.9%
- Past 5 years
- +18.6%
Why cast iron fails in Florida
Cast iron was the standard material for drain, waste and vent lines for decades. Florida conditions are hard on it. Most houses sit on concrete slabs with the drains buried underneath, the climate is humid, and sewer gases inside the pipe corrode the metal from the inside out. The bottom of the pipe, where water runs, often wears through first. Inspectors call that channeling.
Other failure points:
- Cracks and breaks from age, settling or roots.
- Scale buildup that narrows the pipe and causes slow drains and repeated backups.
- Separated joints where sections meet.
Cast iron can last a long time in some houses and fail early in others. Age alone doesn't tell you the condition. A camera does. Two houses on the same street, built by the same builder in the same year, can show very different pipes on video.
Zillow Home Value Index, mid-tier, seasonally adjusted. Hover to see any date.
Data table
| Month | All homes |
|---|---|
| Dec 2012 | $137,888 |
| Dec 2013 | $159,013 |
| Dec 2014 | $174,323 |
| Dec 2015 | $191,493 |
| Dec 2016 | $208,002 |
| Dec 2017 | $224,615 |
| Dec 2018 | $240,223 |
| Dec 2019 | $250,318 |
| Dec 2020 | $272,004 |
| Dec 2021 | $332,010 |
| Dec 2022 | $393,135 |
| Dec 2023 | $400,867 |
| Dec 2024 | $396,947 |
| Dec 2025 | $376,536 |
| Sep 2026 | $375,361 |
How to inspect drain lines before you buy
A standard home inspection doesn't look inside drain lines. Order a separate sewer scope from a licensed plumber. The plumber runs a camera through a cleanout and records the main line, ideally the branch lines too, and gives you the video.
- Ask for the whole run from the house to the street or septic tank, not only the first section.
- Ask for branch lines under the kitchen and bathrooms if they can reach them. Many failures are in branches.
- Keep the video. It becomes your evidence in negotiation and later for insurance.
- Hydrostatic test: some plumbers plug the line and fill it with water to see if the level drops. It shows leaks but can cause water damage in a failing system. Get the seller's written permission first.
Warning signs on a walkthrough: slow drains in several fixtures, gurgling toilets, sewer smell, cracked tile or damp floors near bathrooms, and receipts for repeated drain cleaning. Ask the seller directly whether the lines have ever been scoped, lined or partially replaced.
- Monroe County$963K
- Walton County$661K
- Collier County$552K
- Miami-Dade County$523K
- St. Johns County$493K
- Nassau County$485K
- Palm Beach County$476K
- Martin County$448K
- Broward County$422K
- Franklin County$422K
- Manatee County$408K
- Gulf County$404K
Show all 67
- Orange County$401K
- Seminole County$400K
- Sarasota County$399K
- Sumter County$388K
- Hillsborough County$376K
- St. Lucie County$371K
- Pinellas County$369K
- Indian River County$364K
- Lake County$360K
- Osceola County$359K
- Okaloosa County$353K
- Santa Rosa County$351K
- Flagler County$350K
- Bay County$343K
- Brevard County$342K
- Clay County$335K
- Lee County$334K
- Pasco County$328K
- Volusia County$325K
- Baker County$314K
- Gilchrist County$306K
- Hernando County$306K
- Jefferson County$306K
- Alachua County$299K
- Charlotte County$299K
- Polk County$296K
- Duval County$294K
- Leon County$291K
- Okeechobee County$289K
- Levy County$287K
- Wakulla County$286K
- Escambia County$280K
- Hendry County$270K
- Citrus County$269K
- Marion County$268K
- Columbia County$268K
- Suwannee County$267K
- Lafayette County$262K
- Glades County$257K
- Union County$257K
- Bradford County$253K
- De Soto County$250K
- Hardee County$235K
- Highlands County$231K
- Washington County$221K
- Dixie County$218K
- Putnam County$216K
- Hamilton County$207K
- Madison County$206K
- Liberty County$201K
- Gadsden County$200K
- Taylor County$197K
- Holmes County$181K
- Jackson County$180K
- Calhoun County$167K
Zillow index, highest to lowest.
- Miami$584K
- Boca Raton$580K
- Miami Beach$531K
- Coral Springs$522K
- Miramar$520K
- Davie$515K
- Fort Lauderdale$510K
- Plantation$492K
- Pembroke Pines$487K
- Miami Gardens$474K
- Hialeah$444K
- Hollywood$442K
Show all 40
- Homestead$437K
- West Palm Beach$405K
- Boynton Beach$404K
- The Villages$392K
- Port St. Lucie$384K
- Tampa$376K
- Orlando$373K
- Riverview$363K
- Sunrise$361K
- Melbourne$358K
- Kissimmee$355K
- Brandon$353K
- St. Petersburg$352K
- Pompano Beach$350K
- Palm Coast$344K
- Clearwater$341K
- Largo$336K
- Cape Coral$335K
- Lakeland$309K
- Fort Myers$305K
- Palm Bay$303K
- Spring Hill$303K
- North Port$303K
- Deltona$298K
- Gainesville$292K
- Tallahassee$291K
- Jacksonville$285K
- Deerfield Beach$272K
Zillow index, highest to lowest.
What insurers look at: cast iron, galvanized and polybutylene
Most Florida insurers require a 4-point inspection on older homes. It covers roof, electrical, HVAC and plumbing, and the plumbing section records the supply and drain materials, the water heater age, and any leaks.
- Polybutylene supply lines are gray plastic pipes installed roughly from the late 1970s into the mid-1990s. They were linked to sudden failures, and many Florida insurers decline to write homes that still have them or require replacement first.
- Galvanized steel supply lines corrode and clog with age. Many carriers decline them or set conditions.
- Cast iron drains are treated differently from carrier to carrier. Some accept them if the 4-point shows no active leaks. Others want proof of recent replacement or lining.
- Copper, CPVC and PEX are generally acceptable.
Florida policies also commonly limit coverage for water damage that leaks slowly over time, and drain pipe deterioration itself is usually excluded as wear and tear. Read the exclusions and the water damage section on any quote. Get quotes during your inspection period, while you can still cancel.
Repair options and how they change the deal
There are three broad fixes, each with its own trade-off:
- Spot repair of a broken section. Cheapest, but the rest of the old pipe remains.
- Pipe lining inserts a resin liner inside the existing pipe, cured in place. It avoids most demolition but depends on the pipe's shape and condition, and the plumber has to clean the line first.
- Full replacement with PVC. Under a slab, that means tunneling under the foundation from outside or cutting trenches through the floors. It's the most disruptive option and usually the most expensive.
Get a written quote from a licensed plumber before your inspection period ends. A quote on letterhead carries more weight with a seller than an inspector's general comment. With an as-is contract, you either negotiate a price reduction or credit, or cancel within the inspection period. Lenders limit how large a seller credit can be, so a price reduction is sometimes cleaner.
Which Florida homes are most exposed
The risk follows the age of the housing. Older urban and inner-suburban neighborhoods built from the 1950s to the early 1970s carry the most cast iron. Coastal counties that grew early are full of these houses. Newer suburbs built mostly after the 1980s use PVC drains, though some 1980s and 1990s homes have polybutylene supply lines instead, which is its own insurance problem.
Price doesn't tell you much here. A house in a high-value county such as Palm Beach at $475,754 or Miami-Dade at $523,240 can carry the same original drains as a house in Polk at $295,509. In all of them, the repair cost is roughly the same size, so it hits a lower-priced home harder as a share of its value.
Renovated houses deserve the same scrutiny. A flipped 1960s house can have new floors, new cabinets and a new roof on top of the original drains. New tile laid over failing pipes makes the eventual repair more expensive, because the floor gets cut twice. Ask the seller for the plumbing permit if they say the house was repiped, and check the permit history with the city or county. A repipe without a permit is a question for your inspector and your insurer. Supply line repipes and drain replacements are separate jobs, so confirm which one was actually done.
Condos and townhouses
In a condo, the main drain stacks are usually common elements owned by the association. Your unit's branch lines may be yours or the association's depending on the declaration. Read the maintenance responsibility section in the condo documents.
Several older Florida buildings have done or are planning building-wide drain replacements. Those projects can show up as special assessments. Ask for board minutes, the current budget and the Structural Integrity Reserve Study, and ask the manager whether a plumbing project is planned. In a townhouse with an HOA, the lines under your unit are usually yours.
This isn't legal or insurance advice. A plumber, your inspector and an independent insurance agent can each answer their part for the specific address. If several houses on your list are from the same era, a shortlist sorted by year built helps you plan which ones need a scope.
What buyers ask me
Can you get homeowners insurance in Florida with cast iron pipes?
Often yes, depending on the carrier and the 4-point inspection. Some insurers accept cast iron drains with no active leaks; others want evidence of replacement or lining. Get quotes on the specific house during your inspection period.
What year did Florida stop using cast iron pipes?
There wasn't a single cutoff year. PVC drains became standard in most Florida construction through the 1970s, so homes built before the mid-1970s are the most likely to have cast iron. Check the actual house with a camera scope.
Does homeowners insurance cover cast iron pipe replacement?
Usually not the pipe itself, because gradual deterioration is generally excluded. Some policies cover sudden water damage and limited tear-out costs. Read the policy's water damage terms.
Is polybutylene plumbing insurable in Florida?
Many Florida insurers decline homes with polybutylene supply lines or require replacement before binding. Plan for a repipe if the 4-point shows it.
How much does a sewer scope cost?
It's a modest fee compared with the repair it can reveal. Prices vary by plumber and area, so get a quote when you book the inspection.

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Data: Zillow Home Value Index (ZHVI), Zillow Research, latest month September 2026; U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Figures for small areas carry margins of error. These are planning numbers, not an appraisal of any property.