Complete Guide to Polybutylene Pipes and Why You Should Replace Them

If you own or are considering purchasing an older home, it’s important to understand the risks associated with polybutylene (PB) plumbing. Once a popular choice for residential water lines, PB piping was widely used between the late 1970s and the mid-1990s. However, widespread failures and a major class action lawsuit soon led to its discontinuation and removal from building codes.

Many older homes still rely on aging PB plumbing, putting them at risk of chemical poisoning, sudden leaks, and extensive water damage. In this guide, we’ll explain what polybutylene piping is, how to recognize it in your home, and what to expect if you decide to replace it.

What are polybutylene pipes?

Polybutylene (PB) pipes are a flexible plastic resin piping material that was discontinued in the mid-1990s. Installed in 6–10 million homes, PB piping was favored for its low cost and ease of installation. However, the material proved incompatible with common disinfectants in public water systems, and exposure to chlorine and other oxidants eventually caused the inner surface of PB pipes to deteriorate.

Why polybutylene pipes are a problem

As polybutylene pipes age, their weaknesses become more apparent and more costly. The most common issues homeowners face with PB piping include:

Chemical degradation: PB reacts with chemicals like chlorine and fluoride commonly found in municipal water. Over time, these chemicals contribute to the pipes becoming brittle and failing.
Water contamination concerns: As PB breaks down, it releases microplastics and chemical residue into your water supply.
Repair limitations: Since PB is no longer manufactured, damaged sections can’t be replaced with matching material. Full replacement is the only long-term solution.
Limited or denied insurance: Most home insurance policies won’t cover damage caused by PB pipes, and some insurers may deny coverage entirely.
Resell issues: Homes with PB plumbing can be harder to sell, may sell at reduced prices, or may need to be replumbed before selling.

With a lifespan of only 10 to 15 years, any PB plumbing still in service since production ended in the 1990s is well beyond its intended use.

Warning signs of failing polybutylene pipes

If your home has PB pipes, watch out for:

Water leaks or puddles near plumbing lines
Unexplained drop in water pressure
Discolored or cloudy tap water
Water damage (such as stains, mold, or mildew)
Visible pipe damage (cracking, blistering, or deformation)

In short, PB pipes are no longer just outdated—they are a liability. Their tendency to fail, combined with the challenges of repair, insurance coverage, and resale, makes them one of the most problematic plumbing materials still found in homes today.

How to identify polybutylene pipes

If your house was built before 1990 and the plumbing has never been updated, you may have polybutylene pipes. Since PB was often installed throughout entire systems, finding one section is usually enough to confirm its presence elsewhere. Checking common locations and material features can help you identify it.

Where to look

Polybutylene pipes are often visible in areas where plumbing is exposed or easy to access, including:

Under sinks
In basements and crawl spaces
Connected to water heaters
Along unfinished ceilings or walls

What to look for

Once you’ve located exposed sections of piping, pay attention to the following characteristics:

Color: Typically light gray or light blue
Material: Flexible, rubbery plastic
Markings: A “PB” stamp followed by a number printed on the pipe's surface

how to identify polybutylene (PB) piping

PB pipes can resemble other types of plastic piping, especially PVC or CPVC. The differences are often subtle, so it’s important to check the markings. If you’re unsure about the type of piping in your home, the safest approach is to consult a licensed plumber or review past inspection records and permits.

6 benefits of replacing polybutylene pipes

Replacing PB plumbing can feel like a large undertaking, but the advantages outweigh the inconvenience. If your home contains PB plumbing, proactive replacement is the most effective way to protect your home from water damage and preserve its value.

1. Protects your home from water damage

PB pipes are known to fail without warning. Replacing them reduces the risk of leaks, flooding, and costly repairs to walls, flooring, and personal property.

2. Improves water quality

As PB pipes degrade, they may release microplastics and chemical residue into your drinking water. Upgrading to a safer material, like PEX or copper, can help protect your water supply and health.

3. Restores water pressure and flow

Degrading PB piping can narrow internally, leading to reduced water pressure. New plumbing ensures more consistent pressure and better flow throughout your home.

Learn more: How to Use a Pressure Gauge

4. Increases home value

Homes with modern, reliable plumbing are more attractive to buyers and often sell more quickly. Replacing PB piping is a valuable upgrade that can enhance the resale potential.

5. Reduces insurance risks

Most homeowners' insurance policies won’t cover damage caused by PB piping. After replacement, you’re more likely to qualify for standard coverage—and possibly lower premiums.

6. Eliminates the need for constant repairs

Rather than patching leaks as they occur, replacing your system eliminates ongoing maintenance and the risk of future failures.

While the upfront cost of a repipe may seem high, the long-term benefits far exceed the risks of keeping PB in place. Replacement not only protects your home, but also offers peace of mind that your plumbing will serve you reliably for decades.

What does replacing polybutylene piping involve?

Replacing PB piping usually means a full repipe over 2 to 5 days, depending on the home size. A licensed plumber can replace the system with modern piping, bring everything up to current code, and reduce the risk of future failures.

Here’s what the process usually involves:

1. Inspection and estimate

A licensed plumber will first inspect your plumbing system, confirm the presence of PB, and provide a detailed estimate. Factors such as home size, number of bathrooms, and accessibility of pipes will affect cost and timeline.

2. Accessing the pipes

Since plumbing often runs behind walls, ceilings, and floors, the project may require opening these areas. Plumbers typically try to minimize disruption, but some patchwork and repairs are expected afterward.

3. Installing new piping

New lines are run throughout the home to replace PB. This may also include upgrading fittings, valves, and connections to ensure the system is up to current code.

4. Cleanup and restoration

Once the new system is in place, walls and ceilings are repaired, and water service is restored.

Although a repipe can be disruptive, it provides lasting protection against leaks and water damage. With proper planning and the help of a licensed plumber, your home can be upgraded to a safer, more reliable plumbing system in just a few days.

How much does it cost to replace polybutylene plumbing?

Typical PB pipe replacement costs range from $3,000 to $8,000. Some homebuyers negotiate this cost into the purchase price or request that the seller complete the replacement before closing. Understanding the factors that influence price can help you plan for the project and make informed decisions.

Costs vary based on:

Number of bathrooms
Conditions of your crawl space
Material used for replacement (PEX, copper, etc.)
Labor costs in your area
Whether wall and ceiling repairs are needed
Required permits not covered by the plumber

Every home is different, but investing in new plumbing is far less costly than repairing repeated water damage. Knowing the expected range can help you prepare for discussions with plumbers and factor replacement into home-buying or selling decisions.

What should I replace polybutylene pipes with?

Choosing the right replacement material is just as important as the decision to repipe. Not all options perform the same over time, and some are far better suited for long-term reliability. Here are the most common choices, from the most recommended to the least.

Best choice: PEX (cross-linked polyethylene)

Flexible and easy to install
Highly durable and resistant to chemical degradation
Commonly quality guaranteed for 25–50 years or more
Cost-effective compared to copper

Reliable but expensive: copper

Extremely durable and long-lasting
Resistant to corrosion and disinfectants in public water supplies
Higher material and installation costs
Chosen for highest long-term value

Not recommended: PVC

Prone to becoming brittle over time, similar to polybutylene
May release chemicals into the water as it ages
Not a safe or reliable long-term solution

Selecting a replacement material comes down to balancing cost, durability, and long-term value. For most homeowners, PEX offers the best mix of reliability and affordability, but copper remains an excellent choice when budget allows. PVC, while inexpensive, is generally not a safe long-term solution.

Should I buy a house with polybutylene pipes?

Buying a home with PB piping carries risks. Before you purchase, consider negotiating to have the plumbing replaced or to reduce the sale price to cover the cost. A home inspection should reveal whether PB is present.

Can you sell a house with polybutylene pipes?

While it’s legal to sell a home with disclosed PB piping, it will limit your buyer pool and affect the selling price. Replacing the pipes beforehand is often a worthwhile investment that increases home value and buyer confidence.

Does homeowners' insurance cover polybutylene pipes?

No, most insurance policies exclude coverage for damage related to PB plumbing because the material is known to be defective. If you experience a leak or rupture, the damage may not be covered—leaving you responsible for costly repairs.

Upgrade the quality of your drinking water with Fresh Water Systems

Replacing old polybutylene pipes is the perfect time to upgrade more than just your plumbing. Our water experts can help you choose treatment systems—like filtration or conditioning—that keep your drinking water clean, clear, and free from unwanted contaminants. We’ll recommend solutions that work seamlessly with your new pipes, so your family enjoys water that’s as safe as it is refreshing. Call or message us to explore the best options for your home.

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