What happens when the pipes freeze

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It could turn into The Nightmare on Your Street

Local news in Detroit made national news recently when the pipes in an upscale home froze and broke.

When a water pipe breaks inside a home it can be devastating. In the case of a home in the Boston-Edison Historic District neighborhood, it was spectacularly devastating.

The tenant said a pipe on the third floor broke, causing a virtual waterfall all the way to be basement. Because of the frigid temperatures, the water quickly froze, with huge icicles protruding from the windows, making the structure look like it was something trapped in the Ice Age.

Pipes freezing and breaking during the winter is a fairly common occurrence. We just don't hear about all of them because they usually aren't so over-the-top. But anytime water is cascading unimpeded through your home, it's a very real and personal disaster.

Unheated space

Most of the time your water pipes are safe from freezing. But if they run through any part of the house that isn't heated, or if the heating system fails, the water inside can turn to ice.

When water in a pipe freezes, it expands and puts tremendous pressure on both metal and plastic pipes. If the pipe breaks, it can easily release a torrent of water into the building.

Obeying the law of gravity, the water will gradually work its way to the lowest part of the building, usually a basement or crawlspace.


Water from a broken pipe can not only ruin furniture and other belongings but building materials. In severe cases it can cause structural damage and allow for the growth of mold. Mold, in fact, can be an unpleasant leave-behind, cropping up long after the mess has been cleaned up.

“The presence of mold can impact the indoor air quality for anyone in the building and cause everything from allergies and hypersensitivity pneumonitis to triggering asthma in those with the condition,” said Joseph Frasca, Senior Vice President of Marketing at EMSL Analytical, an indoor air quality firm. “Some types of mold can even cause infections in people with a weakened immune system.”

The cleanup required after a broken water pipe can even expose occupants to asbestos and lead-based paints if it happens in an older building. So for many reasons home owners want to avoid frozen pipes in the winter.

Preventing a broken pipe disaster

Experts at  Popular Mechanics warn that pipes are often most likely to freeze in an uninsulated crawl space. By turning up your thermostat you will keep the floor warmer. Some of that warmth will make its way into the crawlspace – not enough to heat it but enough to keep the pipes from freezing.

The bottom line, they say, is you are better off having a higher than normal heating bill than a flooded crawlspace.

If you know you have an exposed pipe, go to the hardware store and purchase a heating cable. By wrapping the cable around the pipe and plugging it in to an electrical outlet you can transfer a small amount of heat to the pipe during extremely cold weather.

The Red Cross offers these additional tips:

  • Keep garage doors closed if there are water supply lines in the garage.
  • Open kitchen and bathroom cabinet doors to allow warmer air to circulate around the plumbing. Be sure to move any harmful cleaners and household chemicals up out of the reach of children.
  • When the weather is very cold outside, let the cold water drip from the faucet served by exposed pipes. Running water through the pipe - even at a trickle - helps prevent pipes from freezing.
  • Keep the thermostat set to the same temperature both during the day and at night. By temporarily suspending the use of lower nighttime temperatures, you may incur a higher heating bill, but you can prevent a much more costly repair job if pipes freeze and burst.
  • If you will be going away during cold weather, leave the heat on in your home, set to a temperature no lower than 55° F.

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