What Causes Pipes To Burst When They Freeze?

Colder weather always brings an array of potential issues for the homeowner, that’s alongside the increase in heating bills and general energy usage.

One of the most frustrating, and potentially expensive issues, is freezing pipes. When your pipes freeze you suddenly have no water. But, worse than this, you may find that your pipes burst, potentially flooding your home as they defrost.

While your insurance can cover the physical cost of a flood, sentimental items cannot be replaced and there is a disruption element that is rarely accounted for.

Preventing this and other issues with your plumbing appliances is one of the reasons why you should have your hot water systems checked every year.

What is interesting is that most people assume that frozen pipes burst because the ice expands and causing the pipe to rupture.

While this is theoretically possible, it is not usually the issue.

When water freezes it forms into hexagonal crystals; this is an expanded version of water and takes up more space than the water does. This forces the ice to grow in the only direction possible, along with the pipes. However, eventually, the pressure of the water in the pipes against a closed faucet will give the ice no more room to expand. At this point, it will look for another way to expand. The pressure of the frozen water will find a weakness in the pipe; usually where the ice meets the water. This will then rupture, causing a small amount of unfrozen water to escape.

Once the pipes start to defrost the ice in the pipes will turn to water, and come out the hole in the pipe.

That’s why the pipe usually bursts inside your home, the pressure upstream of the ice can be alleviated as the water can retreat, with the help of ice pressure, ultimately returning to its source.

Preventing Pipe Issues

There are several things you can do to help prevent your pipes from bursting.

The first is to check which pipes are most exposed to the cold, these will be the ones outside the building, or under it. Insulate these with a foam or fiberglass sleeve, that will help to prevent them from freezing.

You can also leave your faucet on, dripping slightly. This will prevent the pressure from building up inside the pipes as the water has somewhere to escape to.

You can also choose to drain the pipes, especially if you are going to be away from the house. To do this you’ll need to shut off the water at your mains faucet. Then turn on all your other faucets until no more water comes out. Your house will now have a minimal amount of water in the pipes and certainly not enough to cause an issue if the water does freeze.

Of course, this is not a viable option if you are living in the house every day.

If your pipes do freeze and then defrost, make sure you keep a close eye on where they run through your home; any damp patches that start to appear could indicate an issue with the pipes.