Do Plastic PVC Pipes Freeze & What to do with Frozen PVC Pipes

Can your PVC pipes freeze? Can PVC pipes burst? What should you do if you have frozen PVC pipes?

In this guide you will learn:

  • How and when PVC pipes freeze.
  • Common problems with PVC pipes.
  • Safe ways to thaw your frozen PVC pipes.

Do PVC Pipes Freeze?

The answer to this question is yes, PVC pipes are at risk of freezing during sufficiently cold weather. The reasons why this happens will be discussed later in this article.

Will PVC Pipes Burst When Frozen?

PVC pipes respond differently to the cold than other types of pipes. Rather than bursting in the way a copper pipe would burst, a PVC pipe is more likely to crack and split. PVC is quite a brittle material that struggles to contract and expand when dealing with the cold. 

As such, if water freezes within the pipe, pressure will begin to build up. The buildup in pressure is primarily caused by water being trapped by the frozen section and having nowhere to go. If left untreated, this pressure can lead to the pipes cracking.

Another thing to note is that underground pipes are also at risk of freezing. While the water within may be somewhat insulated by the earth, the soil is still a major issue. If soil freezes and thaws, the soil may move which could cause the PVC pipes to break.

How Cold Does It Have To Be For PVC Pipes To Freeze?

Similar to copper pipes, PVC pipes are at risk of freezing when temperatures drop below 20 degrees Fahrenheit. This can be managed by properly insulating your pipes. We will discuss various methods of insulation later in this article.

PVC vs PEX 

There are several differences between PVC and PEX pipes that affect how they will respond to cold weather. 

Before we get into the differences, we will give you a brief description of both.

PVC pipes are made from Polyvinyl Chloride. PVC pipes are also affordable and last a long time (up to 70 years if properly maintained). PVC pipes are also easier to recycle than PEX pipes.

However, PVC pipes are vulnerable to UV light, such as from the sun. Long periods of exposure can cause the pipes to become brittle, making these pipes best suited for underground and indoor uses.

PEX pipes, on the other hand, are made of Cross-Linked Polyethylene. While slightly more expensive than PVC pipes, they are more suitable for drinking water.

Regarding how they interact with cold weather, some of the differences include:

  • PEX can handle a broader range of temperatures: PVC pipes are more likely to freeze and crack when temperatures drop than PEX pipes. As well as this, they are also more resistant to hot water. During a cold snap, PEX can resist the cold better than PVC can.
  • PEX can bend more: PEX pipes can bend more than PVC pipes, making them easier to install and less likely to leak. This is because they have fewer connection points from which water can escape. Due to this flexibility, PEX can handle the cold better than PVC.

With all this in mind, PEX is considered by many to be more resistant to the cold than PVC. 

Common Issues With Frozen PVC Pipes

Having your pipes freeze on you is a big problem. Some of the common issues with frozen PVC pipes include:

  • No Water: This is the first problem you will notice if you have frozen pipes. Having low or no water coming into your home can be frustrating at best, as it makes even the most basic of tasks (such as having a shower) next to impossible. It may also cost you a lot of money if you have to keep buying bottled water to stay hydrated.
  • Water Damage: Even a small amount of water can cause a surprising amount of damage. Water can quickly destroy electronics, furniture, and carpets. This damage can be expensive to repair and may require the assistance of professionals.
  • Damage to structures:  This is one of the most worrying issues that can come from a frozen pipe. If your frozen PVC pipes leak or crack, the water could rot away at vital supports for your house. Damage to the structures and foundations of the home is dangerous and needs to be dealt with by a professional as soon as possible.
  • Mold Growth: Leaking water from frozen PVC pipes can encourage mold growth. Exposure to mold growth can cause a variety of health issues, including throat and eye irritation, wheezing, and coughing.
  • Costly Replacements: Finally, replacing damaged PVC pipes can be expensive. While PVC pipes themselves are not costly, getting a qualified plumber in to do the job can cost quite a bit.

How To Safely Unfreeze Frozen PVC Pipes

Frozen PVC pipes present a sizable risk to your home. As such, knowing how to safely thaw them is of paramount importance. The steps you need to take to safely thaw out your PVC pipes are:

1: Know the signs

Several signs may suggest your pipes are frozen. These include:

  • No water coming out of your pipes is an obvious sign that your pipes are frozen. A freeze in your pipes makes it impossible for water to get to your taps.
  • Strange smells coming from your drain. If water struggles to flow away, it may become stagnant and begin to smell.
  • Noisy pipes are further evidence that your pipes may be frozen. If your pipes are making any noise, particularly a gurgling noise, that could be caused by increased pressure on the pipes –  a clear sign of freezing.
  • Another clear sign is if there is frost on your pipes. If it is cold enough for frost to form on your pipes, that means it is cold enough for the water inside to freeze.

These tips should help you effectively locate any frozen pipes.

2: Prepare to thaw

Before you can start thawing a frozen pipe, you must prepare the area you will be working. Firstly, turn off your water supply. If you thaw out the frozen water and your water supply is on, it could gush out quickly. As well as this, have a mop, bucket, and plenty of towels on hand to clean up any water that comes from the thawing pipes.

3: Thawing your pipes

Once you have prepared the area, there are a few ways to thaw PVC pipes:

  • Hairdryer: A simple hairdryer is a great way to start thawing a frozen pipe. Just point the hairdryer at the frozen pipe to thaw the pipe.
  • Heat Lamp: A heat lamp is another way to help thaw pipes. The heat from the lamp can thaw the ice within the pipe quickly. Make sure that the lamp does not come in contact with any water that comes from the thawing pipe.
  • Hot Towels: Setting hot towels directly onto a frozen pipe can unfreeze it, while also absorbing some of the runoff.

How To Keep PVC Plastic Pipes From Freezing 

Thankfully, there are many ways to prevent PVC pipes from freezing. Some ideas on how to prevent this from happening include:

  • Insulate Pipes: The simplest way to prevent PVC pipes from freezing is to thoroughly insulate them. There are a variety of ways this can be accomplished. 
    • Firstly, foam pipe insulation is the simplest way of preventing the cold from getting in. This layer of foam can keep water up to 4 degrees hotter than it otherwise would be.
    • Another option is heating tape. There is some discussion about whether heating tape should be used with PVC pipes. While there is some risk of damaging your pipes with heat tape, this can be reduced by using self-regulating heat tape, which manages the heat along the tape to prevent damage.
  • Opening the faucet: Opening the faucet is another way to prevent your PVC pipes from freezing. Running water is much harder to freeze than stationary water. Even just a trickle can prevent your pipes from freezing.
  • Adjust the thermostat: Turning the thermostat up throughout your house can also help avoid freezing. Consistent temperatures throughout the house make it difficult for water to freeze, keeping your pipes safe.
  • Seal leaks: Cracks and openings in your PVC pipes dramatically increase the risk of freezing. Repairing these should be your priority if a cold spell is coming.
  • Open cabinets: Opening the cabinets can make it easier for warm air to spread throughout the house, helping to keep pipes warm.

When To Call A Professional

The best time to call a professional is before the problems arise. If you get a qualified plumber to check your pipes once every 1-2 years, you will likely avoid any major issues.

However, you should call a plumber immediately if either of the following are affecting your PVC pipes.

Firstly, call a plumber if your PVC pipes have burst. These need to be repaired immediately. It is also necessary to call a plumber if you notice any water damage. If either of these occurs, you should call a professional as soon as possible. In summary, ask yourself this question. Do I feel confident performing repair work by myself? If the answer is no, you should call a professional.

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