Water bursting through frozen pipes is a common sight in homes during periods of very cold weather. You’d be surprised how many calls water damage restoration companies, such as PuroClean, get every winter to restore properties that are affected by frozen pipes. Check out how pipes freeze, how to prevent pipes from freezing, and how to unfreeze pipes — and avoid water damage before it’s too late:
Why do pipes freeze?
Pipes are especially vulnerable to damage caused by expanding water. Water lines that freeze are usually exposed to severe cold, such as outdoor hose bibs, swimming pool supply lines, or water sprinkler lines. In addition, pipes in unheated interior areas such as basements, crawl spaces, attics, garages, and kitchen cabinets, and those that run against exterior walls with little or no insulation are also susceptible to freezing.
Several variables contribute to frozen pipes:
- The type of building construction
- The quality and quantity of insulation
- The decline in temperature
- The direction and force of the wind
- Other weather-related conditions are all contributing factors
Furthermore, buildings that have a poor design and do not withstand severe weather sufficiently can contribute to their own damage. The type and age of the plumbing system is also a factor. Rust or corrosion weakens pipes, making leaks more likely to occur. When freeze-expansion occurs, corroded pipes will often split open. When thawing begins or when the water is turned back on, damage can occur.
During the renovation of older homes, blown-in or foam insulation is sometimes added to wall cavities between interior and exterior wall surfaces and between studs. This process may actually insulate heat away from pipes adjacent to the exterior wall surfaces, making them more susceptible to freezing.
Surprisingly, pipe freezing can be a particular problem in the warmer climates of southern states. In these areas, buildings may not be adequately constructed for cold weather conditions. Pipes often run through non-insulated or under-insulated attics, crawl spaces, or walls. If the temperature drops below freezing for even a day, these pipes may freeze and break.
Damage generally occurs when the water supply is turned back on. Since most modern plumbing lines are inside walls, homeowners usually observe a leak only after water has damaged floors, carpet, walls, or ceilings. Occasionally, an occupant hears the sound of spraying water, but by then it may be too late. The leak has already caused some degree of damage.
Pipes can also freeze during a power outage. Winter wind, snow, and ice storms frequently damage electric power lines and equipment, resulting in interruptions of electric power. Most heating systems depend on electricity, and when the power goes off, so does the heat. In severe cold weather, this can result in extensive freeze damage before power is restored.
How water pipes freeze
Water is a unique substance. As with most materials, when water cools, its density increases, and it settles to the bottom of a container. However, at 32º F, it expands and, therefore, its density decreases! This is why ice floats.
This expansion increases the volume of water by about 11% and creates tremendous pressure on its container (between 50,000 and 114,000 psi). Such containers include metal and plastic pipes. No matter the strength of a material, expanding water will cause it to break.
Frozen water pipes can result in significant to extreme water damage, and the cost to repair is often huge! The following tips can help you prevent pipes from freezing and thaw those that are already frozen.
How to prevent pipes from freezing
- Drain water from swimming pool and water sprinkler supply lines following manufacturer’s or installer’s directions. Avoid putting antifreeze in these lines if possible (keeping in mind that antifreeze is environmentally harmful, and is very dangerous to humans, pets, wildlife, and landscaping).
- Drain your plumbing system thoroughly. If water lines sag or bow, there may be low spots that are difficult to drain completely. To be most effective, use compressed air to blow out the lines. If not properly done, some amount of water will remain in the low points of the lines that can freeze.
- Disconnect, drain, and store hoses used outdoors. Close inside valves supplying outdoor hose bibs. Open the outside hose bibs to allow water to drain. Remember to keep the outside valve open so that any water remaining in the pipe can expand without causing the pipe to break.
- Check in the basement, crawl space, attic, garage, and under kitchen and bathroom cabinets where water supply lines are located in unheated areas.
- Insulate both hot and cold water pipes in these areas to help prevent freezing. Use specific products for insulating water pipes like a “pipe sleeve” or installing UL-listed heat tape, heat cable, or similar materials on exposed water pipes.
- Allow a faucet in your home to drip slightly. Moving water (even a drip) will help prevent pipes from freezing.
- During cold winter weather, 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 out of the reach of children.
When leaving home for more than a few days
If you plan to be away from home for an extended period during cold weather:
- Leave the heat on in your home. Set it to a temperature no lower than 55° F.
- Shut off the water supply and drain pipes or appliances.
- Leave all taps open once you’ve shut off the main water supply. If the home loses power, the open valves will help prevent pipes from bursting. Also, shutting off the master valve will ensure that even if there is a break, the result will be minor, compared to an open line running wild!
- Even if you do all the above, arrange for a neighbor to walk through your home once each day – just to help monitor against unforeseen events.
- Have emergency numbers handy such as a plumber, electrician, roofer, and PuroClean in case something does go wrong.
- Have your HVAC system serviced by a professional.
- Before leaving, turn off your water heater. (See owner’s manual for procedures.)
- Install storm windows and/or close shutters to keep in the heat.
- Clean gutters and downspouts to ensure proper water drainage.
- Service your sump pump to ensure proper operation. Adding a backup power source is prudent.
- Unplug all nonessential electric appliances.
- Inform local police if you will be out of town.
How to unfreeze pipes
- Locate the Frozen Pipe – If you’re not sure which pipe is frozen, turn on all faucets in your home. Check which faucet isn’t releasing water at all or just a trickle. The pipe leading to that faucet is likely frozen. Check all other faucets in your home to find out if you have additional frozen pipes. If one pipe freezes, others may freeze, too.
- Turn on the Faucet – Once you’ve located the frozen pipe, open the faucet leading to the frozen pipe. Open both the hot and cold handles. This will allow water to flow once you start thawing the pipe.
- Start Thawing Near the Faucet – When thawing a frozen pipe, the best practice is to start closer to the faucet then work your way down to the frozen section. If you start closer to the blockage, the melting ice could get stuck behind the blockage. This creates more pressure in the pipe and increases the chances of the pipe breaking.
- Thawing Exposed Pipes – There are several ways to thaw pipes that you can access:
- Point a hairdryer at the frozen pipe, starting near the faucet. Follow proper safety precautions for the dryer and don’t come in contact with water when using the dryer.
- Wrap hot towels, which have been dipped in hot water, around the frozen pipe. This method is slower but potentially safer than the ones above.
- Apply electric heat tape directly to the pipe. This tape insulates the pipe, defrosting it. You can leave the heat tape on the pipe and turn it on/off when you need to.
- Thawing Enclosed Pipes – You can thaw pipes that you don’t have direct access to in different ways:
- Turn the heat up in your home and wait until the increased interior temperature thaws out the frozen pipe.
- Position an infrared lamp in front of the portion of the wall where the frozen pipe is located. The heat from the lamp could penetrate the wall and help the pipe defrost.
- As a last resort, cut out the section of the drywall in front of the frozen pipe to easily access it. You can then use one of the methods for thawing exposed pipes.
- Know the Risks:
- When trying to thaw a frozen pipe yourself using a heat source, you run the risk of injury and fire.
- Make sure to take proper safety measures when using electrical equipment.
- In addition, if you don’t start thawing near the faucet, the pipe could burst and cause water to flow into your home.
- Also, do not use a blowtorch, kerosene or propane heater, charcoal stove, or other open flame devices!
- After pipes have thawed, turn off all water to faucets and the icemaker, and monitor the water meter for any unseen leaks.
What to do if a pipe bursts
If a pipe bursts, shut off the water at the main valve. Call a plumber (keep an emergency number nearby for quick access). Then call PuroClean to evaluate and remediate any water damage that occurred. Our technicians stand ready to provide water damage restoration services to your property 24/7.