Pipes Bursting
When water freezes, it expands. That’s why a can of soda explodes if it’s put into a freezer 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…pipes freezing.
Our pipes here in San Antonio are more vulnerable to winter cold spells because one day it is hot and the next it is freezing cold. The pipes built in San Antonio Homes are more likely to be located in unprotected areas outside of the building insulation, and homeowners tend to be less aware of freezing problems, which may occur only once or twice a season.
Pipes in attics, crawl spaces and outside walls are all vulnerable to freezing as well, especially if there are cracks or openings that allow cold, outside air to flow across the pipes.
Holes in an outside wall where television, cable or telephone lines enter can provide access for cold air to reach pipes. The size of pipes and their composition have some bearing on how fast ice forms, but they are relatively minor factors in pipe bursting compared with the absence of heat, pipe insulation and exposure to a flow of subfreezing air.
When is it Cold Enough to Freeze?
When should homeowners be alert to the danger of freezing pipes? That depends, but here in San Antonio, where freezing weather is the exception rather than the rule; listen to your local weather station for warnings of a freeze coming.
Cracks and holes in outside walls and foundations near water pipes should be sealed with caulking to keep cold wind away from the pipes. Kitchen and bathroom cabinets can keep warm inside air from reaching pipes under sinks and in adjacent outside walls. It’s a good idea to keep cabinet doors open during cold spells to let the warm air circulate around the pipes.
Letting the Water Run
Letting a faucet drip during extreme cold weather can prevent a pipe from bursting. It’s not that a small flow of water prevents freezing; this helps, but water can freeze even with a slow flow.
Rather, opening a faucet will provide relief from the excessive pressure that builds between the faucet and the ice blockage when freezing occurs. If there is no excessive water pressure, there is no burst pipe, even if the water inside the pipe freezes.
A dripping faucet wastes some water, so only pipes vulnerable to pipe freezing (ones that run through an unheated or unprotected space) should be left with the water flowing. The drip can be very slight. Even the slowest drip at normal pressure will provide pressure relief when needed. If the dripping stops, leave the faucet(s) open, since a pipe may have frozen and will still need pressure relief.
If You Suspect a Frozen Pipe
If you open a faucet and no water comes out, don’t take any chances. Call Immediate Response Plumbing your licensed plumber of choice.
If a water pipe bursts, turn off the water at the main shut-off valve (usually at the water meter or where the main line enters the house); leave the faucet(s) open until repairs are completed.
Going on a Trip
When away from the house for an extended period during the winter, be careful how much you lower the heat. A lower temperature may save on the heating bill, but there could be a disaster if a cold spell strikes and pipes that normally would be safe, freeze and burst.
A solution is to drain the water system. This is the best safeguard. With no water in the pipes, there is no freezing. This remedy should be considered even when the homeowner is not leaving but is concerned about a serious overnight freeze.
To drain the system, shut off the main valve and turn on every water fixture (both hot and cold lines) until water stops running. It’s not necessary to leave the fixtures open, since the system is filled mostly with air at that point and not subject to freezing. When returning to the house, turn on the main valve and let each fixture run until the pipes are full again.
