PEX piping is an increasingly popular type of plumbing line. Using cross-linked polyethylene, PEX offers greater survivability and durability than traditional plumbing materials like copper.
Given these factors, many people wonder whether PEX piping freezes at all. The short answer is that PEX does freeze, just like any other plumbing material.
However, it freezes at a low temperature and doesn’t burst like many competing plumbing products. This increases survivability and significantly decreases the risk of water damage.
Quick Takeaways
- PEX piping freezes at or below 20°F, especially if it isn’t insulated.
- This is a similar freezing temperature to copper piping.
- PEX doesn’t burst like copper, instead expanding to handle the pressure of a freeze.
How PEX Piping Reacts to Freezing Temperatures
The polyethylene in PEX has cross-linked chemical bonds. The result is a plastic that behaves like rubber. This is important during freezing and thawing cycles because the elasticity improves the odds that the PEX piping will survive without bursting. PEX piping also has some ability to retake its original shape, as long as it doesn’t suffer catastrophic damage.
Alongside this is the fact that water expands when it freezes. This is actually a fairly unusual behavior in nature, since the vast majority of molecules contract.
If ice develops in a plumbing line, it will expand and create serious pressure. This is why traditional plumbing pipes often burst in winter weather.
Bear in mind, there are limits to the elasticity of PEX pipe. Just as a rubber band can stretch beyond its breaking point, PEX piping can do the same. However, that is highly unlikely to happen in the brief freeze-thaw cycles that occur during the rare times when it gets that cold in the Fort Myers area.
At What Temperature Does PEX Freeze?
The temperature to keep in mind is 20°F. Strictly speaking, the PEX material doesn’t freeze at this temperature. However, the water inside the PEX lines can.
Pipe location makes a big difference in how quickly this happens, though. A problem in our part of Florida is that many houses aren’t aggressively insulated. Also, many homeowners don’t insulate water lines. Consequently, a water line that goes along an outside wall or runs from a water heater in the attic is at greater risk.
Why PEX Performs Better Than Copper or PVC in the Cold
Copper piping has several qualities that make it perform badly in cold weather. Foremost, copper pipes have thin walls. Secondly, copper is a very good conductor. This combination means that the latent heat in the water inside the line dissipates rapidly as the house cools.
This process takes about three hours at 20°F in a pipe with no insulation. It takes about six hours, even if the pipes are insulated.
Copper also contracts as it gets colder. Consequently, the metal’s contraction comes into direct conflict with the water’s expansion. This causes pipes to burst.
PVC piping is a bit better than copper. It has thicker walls and retains latent heat better. However, PVC also becomes brittle in cold weather, making it more likely to fracture if the water inside the pipe freezes and expands.
PEX performs better for multiple reasons
- The best version, PEX-A, handles pressures up to 500 PSI in extreme cold.
- Polyethylene has a bit of give, even as ice expands and pressure builds.
- Its strength characteristics don’t worsen in the cold, unlike copper and PVC.
In laboratory testing, the 24-hour survival rate for PEX at 10°F is radically better than copper or PVC.
Factors That Influence Whether PEX Will Freeze
Location and Insulation
Exterior walls, crawlspaces, attics, and garages are all high-risk areas for any type of plumbing line. These are also often unheated spaces.
Exposure to Outdoor Air
Wind chill also affects pipes. Especially if a pipe has direct exposure to cold air, such as a line running to an outdoor spigot, wind chill can accelerate the freezing process.
Water Flow and Usage
Usage makes a difference, too. Lines that have flowing water don’t freeze as quickly. Many people in the North actually leave their water lines on ever so slightly during cold snaps for this reason. Vacation homes and empty buildings are often at greater risk because no one is around to turn the water on.
Signs Your PEX Pipes May Be Frozen
A frozen line is likely to have reduced or no water flow when you try to turn it on. The line may emit a gurgling or bubbling sound because the flow is weak. Exposed pipes may also have visible frost on the outside if they’re frozen. Lines can also bulge due to internal pressure.
How to Thaw Frozen PEX Pipes Safely
The absolute first step is to turn off the main water supply. More than anything, you don’t want to have water behind the ice exerting even more pressure.
Second, call one of our professionals. Finding the location of the freeze is tough for an untrained person. Also, we have tools that allow us to warm pipes evenly and safely, reducing the risk of damage. If you do attempt to thaw a pipe yourself, absolutely don’t use an open flame or any other high-heat source.
Preventive Steps to Stop PEX from Freezing
The best thing you can do is take preventive steps. Keep rooms with pipes above 55°F. Never turn off the heat to your house entirely, even if you’re going to be away for months. Consider installing a smart thermostat, so you can get alerts in case the heating system quits working. Open cabinet doors to let warm air circulate better, too.
Insulation has immense preventative benefits. Insulate both hot and cold water lines using high-quality insulation. Foam pipe sleeves are usually more than sufficient for our part of the country.
Make a habit of shutting off outside water lines at the end of the fall. Drain excess water by running the line after you turn the indoor valve. Disconnect any hoses, too.
FAQs
Is PEX Freeze-Proof?
No, but PEX holds up better to freezing than copper or PVC.
Can I Just Let the Lines Thaw?
Frozen lines can burst if left unattended to thaw. The problem is less the ice and more the pressure. A professional knows how to relieve the pressure properly.
Do Water Lines Even Freeze in Florida?
Yes, temperatures do get cold enough to freeze water lines. Worse, few Florida homeowners prepare to deal with them.
Protect Your Pipes Before the Next Freeze Hits
The time to take action is when the weather is still on your side. Fort Myers Benjamin Franklin Plumbing is here to help you with everything from installing to insulating PEX piping. We also perform repiping. Folks in Fort Myers, FL, consider us the punctual plumbers.
If you’re worried about the risk of frozen water lines in a Fort Myers home, contact Benjamin Franklin Plumbing right away.