Why Pipes Burst
When water freezes in a pipe, the break is not typically where the ice blockage is, the expansion is not what causes the pipe to burst. A complete blockage of a pipe causes an increase of water pressure between the ice and a closed faucet or spigot. That raised pressure is what causes the pipe to fail. Making sure your pipes are properly insulated will keep them safe from breaking, because they will not be exposed to freezing conditions.
Regional Differences
Most houses in northern climates, like here in New Jersey, are designed to keep the pipes on the inside of the building’s insulation. However, extremely cold weather can still penetrate, as well as holes in the structure or insulation allowing cold air in to reach the pipes. Homes in southern climates tend to be much more vulnerable when cold spells do occur. Not only are these homes’ pipes generally less protected, but the homeowners are less aware of the problems caused by freezing pipes, because the conditions necessary are far less common. The pipes in your attic, crawl space, or outside walls are most vulnerable to freezing, especially if there are cracks or openings that allow cold air inside. The University of Illinois conducted research showing that a wind chill can have a major role in freezing pipes.
When is it Cold Enough to Freeze?
There is no definitive time to start being alert to freezing pipes, as there are many contributing factors. Homes in southern states and warmer climates, with non-insulated pipes, should keep an eye out starting at around 20° F. This does not mean that all freezing occurs when the temperature drops into the teens, so homeowners should always be cautious when the weather is cold, or includes gusts of cold wind.
Mitigating the Problem
Water will freeze when its heat becomes transferred to subfreezing air, so the best way to stop it from freezing is to slow or halt this transfer. In ideal conditions, pipes are kept out of attics, crawl spaces, and away from outside walls. If you are building a new home, be sure to keep proper pipe placement in your plans. In an existing house, a plumber may be able to reroute pipes that are potentially problematic, but the best option for the homeowner is to insulate pipes in their existing positions. Insulation sleeves are be found at hardware stores, and plumbing supply stores and insulation dealers can offer extra-thick insulation for especially cold climates. Cold wind should be kept away from pipes by sealing up any holes or cracks in the walls. Keeping kitchen and bathroom cabinet doors open during cold spells will allow for the circulation of warm air around the pipes. Homeowners can also purchase electric heating tape to run along pipes to keep them from becoming too cold, but must be used with extreme caution. To avoid fire and overheating your pipes, be sure to follow the manufacturer’s instructions for use very carefully. Some have a built in thermostat that will turn heat on when it is needed, and those without a thermostat have to be plugged in each time you wish to use them.
Letting the Water Run
You can easily prevent bursting pipes by letting your faucets drip slightly when not in use. Running water, even just a drip, will not stop your pipes from freezing but it will stop the buildup of pressure that causes the pipe to break. A dripping faucet will waste some water, so be sure to only leave open the faucets that are fed by pipes susceptible to freezing. For a faucet or spigot that uses bot hot and cold water, make sure each contributes to the drip, as they run in two separate pipes. In the event that dripping stops, leave faucet or spigot open. This may be a sign that there is a freeze somewhere along the pipe and closing the faucet would just cause pressure to build up and burst the pipe.
If You Suspect a Frozen Pipe
If you think you may have a frozen pipe, take no chances and call a plumber right away. If a pipe breaks, turn off the water at your main shut-off valve and leave the faucets open until the pipe is repaired. Never use an open flame to try to thaw a pipe; it will damage the pipe and may even cause a building fire. If you want to try to thaw the pipe yourself, try using a hair dryer. Warm the pipe starting at the end closest to the faucet and slowly move towards the freeze. Remember not to use electrical appliances if a pipe has already burst and there is water where you stand.
Going on a Trip
If you are going away during winter for an extended period of time, be cautious of how much you lower the heat. It may save your heating bill but the damage done if a pipe bursts will cost even more to undo. The best safeguard is to drain your water system. Your pipes cannot freeze if there is no water in them. Even if you are not going away but simply concerned about an overnight freeze, consider draining your pipes. To drain, turn the water off at the main shut-off valve and turn on every faucet until water stops running. To refill the pipes, turn the main valve back on and turn on every faucet until water runs smoothly, indicating that the pipes are full again.