If you've ever had the misfortune of having a water pipe freeze and burst, you know first hand about what a devastating impact it can have on your home.
When water freezes, it expands. That's why a can of soda explodes if it's put into a freezer to chill quickly and forgotten. When water freezes in a pipe, it expands the same way. If it expands enough, the pipe bursts, water escapes and serious damage results.
Surprisingly, ice forming in a pipe does not typically cause a break where the ice blockage occurs. It's not the radial expansion of ice against the wall of the pipe that causes the break. Rather, following a complete ice blockage in a pipe, continued freezing and expansion inside the pipe causes water pressure to increase downstream -- between the ice blockage and a closed faucet at the end. It's this increase in water pressure that leads to pipe failure. Usually the pipe bursts where little or no ice has formed. Upstream from the ice blockage the water can always retreat back towards its source, so there is no pressure build-up to cause a break. Water has to freeze for ice blockages to occur. Pipes that are adequately protected along their entire length by placement within the building's insulation, insulation on the pipe itself, or heating, are safe.
Water pipes running through unprotected, unheated crawl spaces and pipes running through walls to the outside are prime candidates for freezing...here are some tips to help prevent that from happening.
Turn off the water supply lines running to your outside taps before the cold weather arrives. There is usually a shut off valve in the water supply line close to where it goes through the outside wall. Once the water is shut off inside, go outside and open the outside taps as well. This will drain any water remaining in the pipe or in the tap, so there's nothing to freeze.
Check any pipes that run close to outside walls. Put some fiberglass insulation or rockwool between the pipe and the wall to help keep the cold away from the pipe.
Insulate any pipes that run through unheated crawl spaces. Wrap them with fiberglass insulation and tape or put preformed pipe sleeve insulation along the pipes, then tape the sleeves in place.
- Install electrical heating tape on any pipes that run through areas that get really cold, like garages.