PEX vs. Polybutylene: Understanding the Key Differences

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When it comes to home plumbing systems, understanding the different types of piping materials is

essential for homeowners and buyers. Two common plastic piping options are PEX and

polybutylene (PB), but they are not the same. Knowing the difference can help you make informed

decisions about your plumbing and home safety.

What is PEX?

PEX stands for cross-linked polyethylene. It is a modern, flexible plastic piping material that has

gained popularity in residential plumbing due to its durability, ease of installation, and resistance to

corrosion. PEX pipes are manufactured through a process called cross-linking, which strengthens

the polyethylene molecules, making the pipe more resilient to temperature fluctuations, pressure,

and chemical exposure.

What is Polybutylene (PB)?

Polybutylene (PB) is another type of plastic piping that was widely used from the late 1970s

through the mid-1990s. It’s typically gray or blue in color. Polybutylene pipes are made from a

different plastic compound and were popular for their low cost and ease of installation at the time.

However, over the years, polybutylene has shown significant reliability issues, including leaks and

pipe failures, due to chemical reactions with water treatment chemicals and aging.

Key Differences Between PEX and Polybutylene

)

Feature PEX (Cross-linked Polyethylene) Polybutylene (PB

Manufacturing Cross-linking of polyethylene Polymerization of butylene

Process molecules molecules

Durability & Highly durable, long-lasting, and Prone to cracking, leaks, and

Reliability reliable failures over time

Flexibility Very flexible, easy to install in tight Flexible but less resilient over

spaces decades

Resistance to Excellent resistance to chemicals Susceptible to chemical reactions

Chemical & Water and water corrosion causing deterioration

Common Use Modern plumbing systems, new Outdated, mostly replaced or

construction removed

Why PEX is the Better Choice

Unlike polybutylene, PEX has undergone extensive testing and is recognized for its durability and

reliability in home plumbing systems. Its manufacturing process creates a material that can

withstand high temperatures and pressures, making it a safer and more effective choice for modern

homes.

Need a Plumbing Inspection?

If you're unsure about your home's plumbing system or considering updates, Kenco Home

Inspection is here to help. Our licensed inspectors can evaluate your plumbing and advise you on

the best options to ensure your home’s safety and integrity.

● Call us today at 561-718-6711

● Email: hello@kenco.org

● Visit us at kenco.org

Trust Kenco Home Inspections to provide expert guidance on your home’s plumbing and

safety.