In this DIY Smarts, Ask This Old House plumbing and heating expert Richard Trethewey demonstrates how and why frozen pipes burst.
- Pipes can freeze if the temperature drops below freezing and the pipes are exposed to that temperature for a prolonged period of time.
- When water freezes, it expands in volume by 9%. When this happens in a closed pipe, the ice displaces the water, which increases its pressure exponentially. If this is allowed to go on for too long, the pipe will burst.
- When a water pipe bursts, an immense amount of water will come pouring out and will not stop until the water is shutoff somewhere upstream. Richard recommends labeling the main water shutoff in the house and ensuring every family member knows exactly where it is so it can be turned off as quickly as possible.
- Once the water has been shut off, call a plumber to have it repaired. Be mindful of any nearby electronics or electrical wiring that may have gotten wet during the burst and be sure to steer clear of it.
- Here are a few tips to prevent the pipes from freezing in the first place:
- Insulate the pipes
- Open cabinet doors on cold days to allow the warmer air from the house to keep the pipes warm
- Slightly open the faucet that’s the farthest away from the water main. Just a few dribbles will work. This will relieve any pressure that could build up if the pipes freeze.
Richard demonstrated that pipes, when frozen, expand in volume, which exponentially increases the water pressure and forces the pipe to burst. In these circumstances, shut the water off at the main and immediately call a plumber.
To prevent the pipes from freezing in the first place, Richard recommended keeping cabinet doors open and insulating the pipes with pipe insulation. This can be found at The Home Depot.