Does PEX pipe need to be insulated?

Author: Sonny Ziemann  |  Last update: Sunday, March 30, 2025

In colder climates, insulating PEX pipes can help prevent the water inside from freezing, which could lead to burst pipes. On the flip side, in hot and humid environments, uninsulated cold water lines may sweat, leading to potential issues like mold growth or water damage. Insulation can help mitigate these risks.

Should I insulate PEX pipes?

It's best practice to pipe insulate your pex 24'' or so in either direction of direct contact with duct work, weather that duct work is insulated or not. Especially in moisture rich environments, heat exchange can cause condensation build up. with enough time moisture damage can occur.

Will PEX pipe freeze and burst?

Key Takeaways. All PEX pipes are flexible and can expand in high-pressure, freezing conditions. PEX pipe is more durable than rigid pipe in cold weather but is still susceptible to burst in extreme conditions.

Is it code to insulate PEX?

PEX tubing does not provide any significant thermal insulation properties and would not meet code requirements without additional insulation.

Does PEX pipe need to be insulated in crawl space?

No. People have misconceptions about insulation. It does not prevent freezing. It just slows the release of heat.

Where to insulate PEX Plumbing Pipe tubing will it freeze bust should be insulated in attic outside

Will PEX freeze in the attic?

It is not likely that PEX pipe will freeze. However, it is possible if it gets cold enough.

Will PEX freeze in exterior wall?

Due to its flexibility, PEX has a small margin of expansion under the damaging pressure caused by ice formation. If the weather gets cold enough, PEX pipes can and will freeze like any plumbing. However, PEX may be less likely to rupture as a result of freezing.

Where should you not use PEX?

PEX pipe can be used as a service line based on its corrosion resistance to soil and water, its long life and its oxidative resistance. Our PEX pipe is not suitable for use in areas where the soil is or may become contaminated, including soil used for backfilling.

Will foam insulation keep PEX from freezing?

We also recommend insulating the parts of your pipe that are often exposed to extreme temperatures. Below are a few tips when insulating PEX pipes: Use foam to insulate PEX pipes. Foam is the most popular insulation material for PEX pipes because they are flexible.

Is PEX plumbing up to code?

PEX Plumbing in your Area

Although PEX tubing is approved by all major building codes and major model plumbing codes, it still has not received acceptance with local codes in some parts of the country. For example, PEX tubing has only recently been allowed for use in the state of California.

How long does PEX last?

PEX often lasts around 50 years. However, PEX is more durable and has more flexibility than PVC and CPVC. Also, because PEX is made from cross-linked polyethylene, it won't corrode.

How to keep PEX from freezing in crawl space?

How to Keep Water Pipes in a Crawl Space From Freezing
  1. Insulate Your Crawl Space. ...
  2. Turn Off Water to Outdoor Taps. ...
  3. Cover Exposed Pipes. ...
  4. Leave Faucets to Drip. ...
  5. Keep the House Warm. ...
  6. Leave Cabinet Doors Open. ...
  7. Shut Garage Doors. ...
  8. Use Heat Cables.

What is the difference between PEX a and b pipe?

PEX A offers higher burst resistance, capable of withstanding up to 500 PSI in extreme cold, while PEX B, being more rigid, is less resilient.

What is negative about PEX?

PEX pipes are very thick but they are still susceptible to rodent damage that can cause pipes to crack or break. Possible Leaching: Although uncommon, some homeowners and plumbing companies have reported a few PEX pipes leaching harmful contaminants like BPA (Bisphenol A) into the water supply.

At what temperature does insulated PEX pipe freeze?

PEX pipes will freeze if the temperature drops to around 20 degrees Fahrenheit or lower. If the pipes are not insulated, they may start to freeze closer to 32 degrees Fahrenheit, which is the freezing point of water. Insulated PEX pipes may be able to withstand some more chill.

Should you put insulation over pipes?

The updated guidelines stipulate that pipes conveying space heating and hot water through unheated areas must now be insulated.

Is it worth insulating PEX pipe?

Insulating PEX Pipes Can Lead to Noise Reduction

PEX piping, due to its flexibility, is often quieter than metal pipes. Yet, water rushing through any pipe can produce some level of noise. Insulation can serve as an added layer that absorbs sound, providing a quieter living environment.

What is the best pipe insulation to prevent freezing?

Use foam rubber or fiberglass sleeves to help decrease the chances of freezing. Insulation can help keep the pipes closer to the temperature of the water inside the pipe, but it does not add extra heat to the pipe and unfortunately will not prevent freezing if the pipe is exposed to prolonged freezing temperatures.

Does spray foam insulation damage PEX pipe?

NOTE 3: While it is not the focus on this Technical Note, plastic pipe materials (e.g., CPVC, HDPE, PEX, PEX-AL-PEX, PE-RT, PP-R, PP-RCT) are not known to have chemical-compatibility issues with properly mixed and applied spray polyurethane foam insulation.

Why do plumbers not like PEX?

Material Concerns: One of the primary concerns about Pex plumbing is the material itself. While Pex pipes are undoubtedly flexible, making them easier to install in tight spaces, they are not as durable as traditional materials like copper or even PVC.

Why is PEX banned in California?

Currently, PEX plumbing is one of the most widely used plumbing systems around the world. It was temporarily banned in California for a while due to concerns about toxic materials but this was later disproven by laboratory tests.

Do mice eat PEX pipe?

PEX Pipe Is Vulnerable

Rodents Chewing Through PEX Pipe is a common problem in our area. It doesn't matter how old your home is, if you have an attic, you need to watch for rodent damage to PEX Pipe or PVC. If you're hearing rustling noises coming from the attic, it's time to do an inspection.

How do you insulate exterior PEX pipe?

Reflective Foil Insulation: Reflective foil insulation is an excellent choice for PEX pipe located in areas with extreme temperature variations. It helps to reflect heat back into hot water pipes and prevents heat gain in cold water lines.

What is the best pipe for freezing conditions?

PEX, or cross-linked polyethylene, has a chemical structure that gives it flexibility to withstand pressure increases and perform better in the winter. If water freezes in the pipe, for example, PEX will expand to accommodate the change. Then it will contract back to original dimensions once thawed.

Should I use copper or PEX?

With a life span that's 20 to 30 years longer than PEX pipe, copper is the clear winner. Properly maintained copper pipes can be expected to last 50 to 70 years. PEX pipes that are properly maintained generally last for 25 to 50 years.

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