Does PEX Piping Have Advantages In Freezing Temperatures?
When subjected to freezing conditions, PEX tubing has several advantages over CPVC pipe as well as galvanized steel and copper pipe.
Many of the facts below were taken from the technical report Resistance Of Pex Pipe And Tubing To Breakage When Frozen, published by the Plastics Pipe Institute.
Freeze Tolerance Features of PEX tubing include:
PEX retains flexibility down to at least -40°C
Water expands when it turns to ice. If the water inside PEX tubing freezes, in most cases it should be able to expand without cracking or splitting, then return to its original diameter upon thawing.
This expansion of water turning into ice can cause rigid piping such as copper, galvanized steel, and CPVC to burst. Furthermore, CPVC pipe and fittings can become brittle in very cold conditions.
PEX has low thermal conductivity
Compared to copper and galvanized steel pipe, PEX transfers heat at a much, much slower rate. This means that if a part of your plumbing system is exposed to freezing temperatures, it will take longer for the water in the pipes to freeze.
PEX plumbing systems use fewer fittings
Copper and other rigid piping systems like galvanized pipe or CPVC require fittings and connections at each turn. These are all potential points of failure in a system subject to freezing conditions.
Flexible PEX tubing can be run in continuous lengths from a central manifold straight to each outlet, with much fewer connections overall. The long, continuous tubing runs, can make PEX less susceptible to failure if water freezes in a section of the system.
PEX can be more easily routed through insulated spaces
Poorly insulated external walls, attic spaces, crawl spaces, and so on: these are some of the risk areas for freezing pipes. As we saw in the Houston Big Freeze disaster - incomplete insulation can be quite common in southern states.
We have another article covering the benefits and costs of a PEX repipe in general. You can also contact us to schedule a free consult with one of our local estimators, who can discuss your repipe options and provide you with a fixed price quote.
Will PEX Piping Break If It Freezes?
Although PEX tubing is the best piping option during freezing temperatures, it can still experience breaks if the water inside it freezes.
There are three ways PEX (and any plumbing) may fail from water freezing:
1) Outward expansion of ice in a pipe
When water freezes and turns into ice, it expands in all directions. The outward expansion of ice in a pipe can cause PEX tubing to expand in diameter (as mentioned in the previous section, this outward expansion can cause rigid pipe to fracture). Since PEX is flexible, there is a low likelihood of PEX failure from freezing for this cause.
2) Lengthwise expansion of ice in a pipe
The larger risk of failure comes from ice forming one or more ice plugs within piping, trapping unfrozen water. As these ice plugs expand lengthwise along the pipe, the trapped water can experience significantly increased pressure. If the pressure gets high enough, it could cause PEX (or any other plumbing material) to fail.
3) Repeated freeze/thaw cycles, weakening pipes and fittings
It is also possible that multiple freeze and thaw cycles over time, could weaken PEX tubing or fittings; but this should not be a significant risk. In a 2016 research project, PEX tubing was subjected to five freeze/thaw cycles under pressure, then subsequently subjected to burst testing. Even test tubing that had been notched (to simulate real-world conditions where some tubing might be partially nicked during installation or in use) demonstrated burst pressures for in excess of the PEX specification of 475psi.
How Can I Tell If My PEX Pipes Are Frozen?
There are several ways to tell if the water inside your PEX tubing has frozen:
- Little To No Water Coming Out Of Faucets: If you turn on a faucet and no water comes out, it may be a sign that your PEX pipes have frozen. This is because ice blockages inside the pipes can decrease water flow.
- Strange Sounds Coming From Pipes: If you hear strange sounds coming from your PEX pipes, such as banging or clanking noises, it could be a sign that there's ice inside the pipes. This occurs when water tries to manoeuvre through frozen areas.
- Frost On Pipes: If you see frost on the outside of your PEX pipes, it's a clear indication that the water inside them may be frozen.
If you suspect that your PEX pipes have frozen, it's important to take action quickly to prevent pipe damage and leaks.
Try to keep water flowing, to avoid any excess build up of water pressure. If you know where the frozen section of pipe is, try to warm that area and/or warm the tubing itself.
How Do I Keep Water From Freezing In PEX Pipes?
The only sure-fire way to avoid freeze-related PEX tubing failure, is to stop water from freezing in your pipes in the first place.
As we've mentioned previously, the biggest problems historically have been in locations that only occasionally experience deep freezes. In the north, where extended cold spells are common, building codes (and the enforcement of freeze-related building codes) usually prevent situations where plumbing can be exposed to freezing and subsequent failure.
We have compiled some options to help minimize the likelihood of water freezing in your PEX pipes:
- Electrical Heat Tape: Electrical heat tape can be used to keep segments of pipe above freezing. The heat tape is typically controlled via a thermostat, and will only kick in below preset temperatures. It is important to match the correct type of heat tape for your specific pipe type. Heat tape is particularly useful for pipe passing through uninsulated areas, where a re-route isn't feasible.
- Rerouting Plumbing: Rerouting plumbing through walls and spaces that are well-insulated and heated.
- Insulate your pipes: Insulating your PEX pipes can help to keep the water inside them from freezing. You can use foam insulation sleeves or tape to wrap around the pipes. It is also worth insulating particularly cold areas such as attic spaces and basements.
- Keep your home warm: It's important to keep the temperature in all areas of your home above freezing. Be particularly careful about areas that may be poorly insulated and not properly heated. Use space heaters if necessary to access hard to reach areas. Much of the damage in the Houston Big Freeze was from pipes bursting in uninsulated attics.
- Let your faucets drip: If you're concerned about your PEX pipes freezing, you can let your faucets drip slightly overnight. This can help relieve pressure that may build up in the pipes and prevent them from bursting, while keeping the water moving inside of your pipes. This is especially important for pipes located outside or in uninsulated attic spaces.
- Seal drafts: Look for drafts around your home where cold air may be getting in and seal them up. This can help to keep the temperature inside your home warmer and prevent your PEX pipes from freezing.
- Install Frost-Free Sillcocks: A Frost-Free Sillcock is a type of freeze-proof valve that prevents your outdoor hose bibs (aka spigot or sillcock) from bursting due to freezing.
By following these steps, you can help to lower the chances of the water in your PEX tubing from freezing and resulting in breaks in the pipes.
If you would like to know more about re-routing your plumbing to avoid the problems that come with extreme weather conditions, we can help advise you on your best options. Contact us today for a free consultation.
Worried About Sudden Freezes? Consider Using PEX.
If you have experienced plumbing issues due to sudden freezes, PEX tubing is the best option to prevent any future problems.
We can advise you on the best options for repiping with PEX tubing. During installation, we will ensure that PEX (or copper) pipes are routed through areas that won't be exposed to freezing temperatures. We can also insulate the pipes as necessary to mitigate the risk of future freeze damage.
It's important to consider a repiping solution that ensures the longevity of your pipes regardless of the conditions.
Our One-Stop Repipe™ Process can be completed in just 1-2 days and comes with a lifetime warranty, ensuring your peace of mind during sudden freezing temperatures.
