If your home was built between about 1978 and 1995, there is a fair chance some or all of its water lines are polybutylene. This gray plastic pipe was cheap and easy to install, so millions of homes got it. Over time, chlorine in city water can make it brittle from the inside, and it can split with little warning.
Replacing polybutylene with PEX costs about $2.70 to $4.00 per square foot of living space, or roughly $4,150 to $6,800 for a 1,500 sq ft single-story home with the permit, before drywall repair. For a figure based on your own home, enter its size, stories and foundation in our house repiping cost calculator.
How to tell if you have polybutylene pipe
Polybutylene is a flexible plastic pipe, most often gray, sometimes blue or black. Check these spots with a flashlight:
- At the water heater: the lines on top of the tank, just past any short metal connectors.
- Under sinks: the pipe coming out of the wall to the shut-off valve.
- Where the main enters: near the meter, in the garage, basement or crawl space.
- Printed code: many PB pipes are stamped PB2110 along the side.
- Fittings: gray plastic or copper crimp rings on the joints.
Some homes have a mix. A previous owner may have replaced the visible pipe at the water heater with copper while the lines in the walls are still polybutylene. If you are unsure, a plumber can confirm it in a short visit.
What polybutylene replacement costs by home size
Replacing polybutylene is a full repipe of the water supply lines. The cost is driven mostly by how much plumbing the home has, which tracks closely with square footage. These ranges cover pipe, labor and the permit, but not drywall patching.
| Home size | PEX | CPVC | Copper |
|---|---|---|---|
| 1,000 sq ft | $2,800 – $4,800 | $4,600 – $6,500 | $6,600 – $12,800 |
| 1,500 sq ft | $4,150 – $6,800 | $6,850 – $9,350 | $9,850 – $18,800 |
| 2,000 sq ft | $5,500 – $8,800 | $9,100 – $12,200 | $13,100 – $24,800 |
| 2,500 sq ft | $6,850 – $10,800 | $11,400 – $15,100 | $16,400 – $30,800 |
Figures are single-story homes on a crawl space. Two-story homes and slab foundations cost more because the plumber has more walls and ceilings to open. Most polybutylene replacements use PEX today, because it is the lowest-cost option and flexible enough to snake through walls with fewer openings. Our PEX vs copper pipe guide compares the two in detail.
Extra costs to plan for
The pipe work is only part of the bill. Ask each plumber what is included, because quotes are often not apples to apples.
| Item | Typical cost | Notes |
|---|---|---|
| Drywall patching and paint | $1.60 – $3.00 per sq ft of home | Some plumbers include it, many do not |
| Permit and inspection | $100 – $800 | Required in most cities for a repipe |
| Each bathroom past two | $600 – $1,600 | More fixtures, more runs |
| Main line from the meter | Varies | Often polybutylene too, priced separately |
Drywall repair alone can add $2,000 to $5,000 on a typical house, so ask whether the quote leaves the holes for you to fix.
Why replace polybutylene before it leaks?
Polybutylene usually fails from the inside, so the pipe can look fine until it splits. A burst inside a wall or ceiling can do far more damage than the cost of a planned repipe. There are three common reasons owners act now:
- Insurance: many insurers raise premiums or decline new policies on homes with polybutylene.
- Selling: buyers' inspectors flag it, and lenders or buyers may ask for a credit or replacement.
- Water damage risk: a single split line can flood a room in minutes. Our guide on what to do after water damage covers the cleanup if it happens.
If you are seeing other warning signs, like low pressure, discolored water or repeat leaks, read our list of signs you need to repipe your house.
How to keep the cost down
- Get three written quotes that list pipe type, number of fixtures, drywall work and permit.
- Choose PEX unless you have a strong reason for copper. It often costs half as much or less.
- Do the drywall yourself or hire a handyman if the plumber's patch price is high.
- Plan it before a leak. Emergency repairs plus water cleanup cost far more than a scheduled job.
- Ask your insurer whether replacing polybutylene lowers your premium.
Run your own numbers in the house repiping cost calculator before you call plumbers, so you know whether a quote is in a normal range.
Frequently asked questions
How much does it cost to replace polybutylene pipes?
Most homes pay about $2.70 to $4.00 per square foot of living space to replace polybutylene with PEX, before drywall repair. A 1,500 sq ft single-story home usually runs about $4,150 to $6,800 with the permit.
How do I know if I have polybutylene pipes?
Look for flexible gray, blue or black plastic pipe marked PB2110, often at the water heater, under sinks or where the main line enters the house. It was common in homes built from about 1978 to 1995.
Will insurance cover polybutylene pipe replacement?
Usually not. Homeowners policies rarely pay to replace pipe just because of its age or type. Some insurers raise rates or refuse new policies on homes that still have polybutylene, which is why many owners replace it.
Can I replace only part of my polybutylene plumbing?
You can, but most plumbers advise against it. The plastic fittings and pipe age together, so a partial fix often moves the next leak to the section you kept. Replacing the whole supply system is the usual choice.
How long does polybutylene replacement take?
Most homes take about 2 to 5 days of plumbing work with PEX, plus a few more days for drywall patching and paint. Water is usually back on each night.
Costs are 2026 national estimates for planning only. Your price depends on your home, your area and the contractor. See how we estimate.