If you live in a home built between the late 1970s and mid-1990s, you might have an outdated—and potentially problematic—plumbing system running behind your walls. It’s called polybutylene plumbing, and while it once promised a cheaper, easier alternative to traditional copper, it’s now infamous for unexpected leaks, costly water damage, and legal issues.
This guide breaks down what polybutylene plumbing is, why it was used, why it failed, and what you should do if it’s in your home.
What Is Polybutylene?
Polybutylene (PB) is a type of plastic resin that was used to manufacture water supply piping from the late 1970s through the mid-1990s. It was developed as a cost-effective and easy-to-install alternative to copper plumbing.
The material was flexible, light, and resistant to cold – it was U.S. The builders and plumbers were popular, especially in Sunbelt states.
When and Why It Was Widely Used
Between 1978 and 1995, over 10 million homes across the U.S. had polybutylene pipes installed. The boom was largely due to:
- Low cost compared to copper
- Ease of installation
- Belief that it would last for 50+ years
Unfortunately, real-world performance didn’t live up to the expectations.
Key Characteristics of Polybutylene Pipes
Material Composition and Appearance
Polybutylene pipes are:
- Typically gray, blue, or black
- Marked with “PB2110” or similar codes
- Flexible and slightly shiny
- Typically ½ to 1 inch in diameter
They were most often installed in hot and cold water supply lines, but not typically in drains or vent systems.
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Advantages When It Was Introduced
At the time, PB pipes were seen as revolutionary:
- Required fewer joints, reducing labor
- Resistant to corrosion (initially thought to be more durable than metal)
- Fast to install in large residential builds
Unfortunately, these advantages were overshadowed by major long-term issues.
Common Applications in Residential Plumbing
Where Polybutylene Was Installed
- Inside walls of homes (especially tract housing)
- Under slabs in one-story homes
- Attics and crawlspaces
- Connecting water heaters to fixtures
Types of Plumbing Systems It Was Used In
PB was mostly used in:
- Potable water distribution (hot and cold)
- Mobile homes
- Apartment complexes
- Single-family homes in new construction during the 1980s and early 1990s
If your home was built during this period and hasn’t been repiped, there’s a strong chance PB may still be present.
The Downside of Polybutylene Plumbing
Chemical Reactions That Cause Deterioration
Polybutylene’s downfall was its inability to hold up under real-world water conditions:
- It reacts negatively with chlorine and other disinfectants found in municipal water.
- Over time, the inner surface of the pipe becomes brittle and flakes.
- This leads to micro-fractures, which eventually cause leaks or pipe bursts.
These failures often occur without warning and behind walls, making them even more destructive.
Issues with Fittings and Connections
Early PB systems used acetal plastic fittings and aluminum bands, which failed at a high rate.
Even upgraded fittings (copper or brass) didn’t eliminate the risk entirely. The problem wasn’t just the connectors—it was the pipe itself.
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Polybutylene Plumbing Lawsuits and Bans
Class Action Lawsuits and Settlements
In the early 1990s, the owners of the US house began to report horrific pipe failures, causing water damage, mold growth and expensive repair. As complaints were piled up, manufacturers like Shell Oil and others faced the growing legal crisis.
In 1995, Cox V. A class-action suit, known as a shell oil company, was settled by $ 950 million, which aims to cover the place of defective polybutilein plumbing in affected homes. However:
- Many homeowners missed out due to deadlines or lack of awareness.
- The settlement fund has long since expired, leaving current homeowners fully responsible for replacement costs.
Why Building Codes No Longer Approve PB Pipes
Due to its poor track record, polybutylene piping was eventually removed from U.S. and Canadian plumbing codes by the mid-1990s.
Today:
- Most municipalities prohibit the installation of polybutylene in any form.
- Insurance companies often deny coverage or increase premiums for homes with PB piping.
- Home inspectors flag PB as a red flag, especially when buying or selling real estate.
How to Identify Polybutylene Pipes in Your Home
If you suspect your home has polybutylene, here’s how to check.
Visual Clues and Pipe Colors
Look for:
- Gray, blue, or black plastic pipes with a diameter between ½ and 1 inch.
- Pipes marked with “PB2110”, “PB”, or similar labels.
- Pipes that are soft, bendable, and slightly glossy.
Be careful not to confuse them with PEX, which is typically red, white, or blue and labeled differently.
Common Locations Where PB Pipes Are Found
- In the basement or crawlspace
- Behind access panels under sinks or near water heaters
- Where pipes enter the water meter
- In attics, especially in warmer climates
If you find one section of PB pipe, there’s a good chance the entire plumbing system is made from the same material.
Risks of Keeping Polybutylene Pipes
Some homeowners choose to live with PB piping because it hasn’t failed—yet. But the risks are real and should not be ignored.
Leak Risk and Water Damage
- PB pipes deteriorate from the inside, meaning problems aren’t visible until it’s too late.
- A sudden pipe rupture behind walls or under flooring can cause extensive water damage.
- Repairing leaks doesn’t solve the root problem—it only buys time until the next one occurs.
Insurance and Home Sale Issues
- Many insurance companies refuse to cover homes with PB piping unless it’s been replaced.
- Others charge higher premiums or impose deductible limitations.
- If you’re selling, potential buyers may walk away—or demand price reductions to cover repiping costs.
PB piping is a liability in real estate and can devalue your home if left unaddressed.
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Replacing Polybutylene Plumbing
If you discover PB pipes in your home, the best course of action is complete replacement—also known as “repiping.”
Best Replacement Materials (PEX, Copper, CPVC)
- PEX: Most popular option today. Flexible, affordable, and easy to install. Resistant to chemicals and freezing.
- Copper: Durable and time-tested, but more expensive and labor-intensive to install.
- CPVC: Inexpensive and widely accepted, but not as flexible as PEX and can become brittle over time.
PEX is generally the most appropriate substitute for PB due to convenience of use, durability and compatibility with modern plumbing systems.
Cost to Repipe a House with PB
The prices vary according to home size, layout, and material used, but typical values are:
| Home Size | Estimated Cost to Repipe |
| Small (1,000 sq ft) | $3,000 – $5,000 |
| Medium (1,500–2,000 sq ft) | $5,000 – $8,000 |
| Large (2,500+ sq ft) | $8,000 – $12,000+ |
These costs include labor, permits, and materials. Costs can increase if walls or flooring need significant patching.
DIY vs. Professional Replacement
When to Consider Doing It Yourself
- You’re experienced in plumbing and local code compliance.
- The PB piping is in unfinished spaces like a basement or crawlspace.
- You have time to do the job carefully, room by room.
DIY replacement is possible, but you still may need a licensed plumber to pull permits or perform the final connections.
Benefits of Hiring a Licensed Plumber
- Ensures compliance with building codes and permit requirements
- Comes with a warranty or guarantee
- Work is completed faster and with fewer errors
- You gain peace of mind knowing it’s done right
In most cases, hiring a pro is worth the investment—especially if you’re repiping your whole home.
How Polybutylene Differs from Other Plastic Pipes
Understanding the differences between polybutylene and other modern plastic piping options can help you make informed choices when it comes to replacement.
Polybutylene vs. PEX
| Feature | Polybutylene (PB) | PEX (Cross-linked Polyethylene) |
| Durability | Poor – prone to failure | Excellent – long-lasting |
| Flexibility | High | High |
| Resistance to Chlorine | Weak – breaks down | Strong – chemically resistant |
| Current Code Approval | Not allowed | Widely approved and preferred |
| Color Options | Gray, Blue, Black | Red (hot), Blue (cold), White |
PEX is the go-to replacement for PB. It’s stronger, safer, and fully accepted by modern plumbing codes. It also shares many of the same installation benefits PB once promised—without the long-term failure rate.
Polybutylene vs. CPVC
| Feature | Polybutylene (PB) | CPVC (Chlorinated Polyvinyl Chloride) |
| Flexibility | Flexible | Rigid |
| Durability | Poor | Moderate to Good |
| Installation Ease | Easy | Requires precise gluing |
| Temperature Tolerance | Moderate | High |
| Approval in Codes | Not approved | Approved in most regions |
CPVC is a solid option, especially for retrofit plumbing in walls or attics. However, it lacks the flexibility of PEX and can become brittle with age.
Conclusion
Polybutylene plumbing was once seen as a revolutionary solution in residential construction—lightweight, affordable, and easy to install. But over time, it became one of the most notorious building materials in the industry, due to its propensity to fail without warning and its incompatibility with treated municipal water.
If your home has polybutylene pipes, it’s not a question of if they’ll fail—it’s a question of when. From legal issues to homeowner’s insurance challenges, the risks far outweigh any benefit of waiting it out.
Replacing PB with modern materials like PEX or copper will not only protect your property—it will also restore peace of mind, improve your home’s value, and make future plumbing work far more manageable.
FAQs
1. Is polybutylene plumbing still used today?
No. Polybutylene was officially discontinued in the U.S. in the mid-1990s and is no longer approved by building codes due to its high failure rate.
2. Is it safe to leave polybutylene pipes in place?
While some systems haven’t failed yet, polybutylene can deteriorate internally without visible signs. It’s strongly recommended to replace it as soon as possible.
3. Will home insurance cover polybutylene pipe failure?
Many insurers either refuse to cover homes with PB piping or increase premiums. Some may deny claims related to PB failure altogether.
4. How can I tell if my house has polybutylene pipes?
Look for flexible gray, blue, or black plastic pipes stamped with “PB2110” in basements, crawlspaces, or under sinks. Have a licensed plumber confirm if you’re unsure.
5. What’s the average cost to replace polybutylene plumbing?
Replacing PB with PEX or copper can cost between $3,000 and $12,000+, depending on home size and layout. The investment can prevent future water damage and insurance issues.
