Preventing and Thawing Frozen Water Pipes

by Karie Fay

Water always expands as it freezes. For some homeowners, this spells trouble come winter. Temperatures drop, water pipes get cold enough to freeze, the water inside expands in the process – and a pipe bursts.

Taking steps now – before anything happens – allows you to avoid the hassle and mess frozen pipes create. If, however, you caught the problem too late and your pipes have already frozen, try thawing the pipes as soon as possible. Knowing how to prevent the problem and what to do if the worst happens will arm you with all the information you need to handle the situation properly.

Is Your Home at Risk?
In colder climates, homebuilders generally enclose water pipes inside the house’s insulation to protect them from extreme cold. Unfortunately, that’s not always enough. If temperatures drop low enough or a problem exists that allows cold air to reach the pipes, it can lead to a burst pipe. Cracks, holes, gaps or inadequate insulation can still lead to frozen pipes.

Homes in southern climates are more vulnerable than their northern neighbors due to the tendency to run pipes outside the building insulation, often in unheated crawlspaces and similar areas. Residents are less likely to be conscious of the problem, and the conditions under which their pipes are likely to freeze only happen a time or two each year, so it has likely never been an issue before … until it happens.

When is it Cold Enough for Pipes to Freeze?

Since plumbing pipes typically run inside the building envelope in colder climates, it usually takes colder outdoor temperatures to freeze. In more moderate regions, the “temperature alert threshold” is 20 degrees Fahrenheit, in contrast to about zero degrees F the cooler regions.

Temperature isn’t the only factor, however. Wind chill – the perceived temperature that results from the combination of temperature and moving air or wind speed – can accelerate freezing water or penetrate deeper into the home than air that is frigid but still. The pipe location also plays a role: A pipe running through the ceiling of an un-insulated basement, for example, would require colder temperatures to freeze completely than a pipe running along an outside wall in the same basement.

Which Pipes are Most Vulnerable to Freezing?

While any pipe or plumbing accessory can freeze, some are more likely to experience problems than others. Pay particular attention to these pipes and locations while performing preventative measures to protect them.

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  Outdoor hose bibs – In the fall while temperatures are still mild, detach any water hoses or accessories. Drain water from the hose, coil and store in a safe place. Next, turn off the water supply to the hose bib if possible. Many homes have a shut-off valve that controls only the outside faucet. Look in the basement or wherever the water first enters the home, from which point it routes throughout the house in various pipes. Turn on the bib outside and allow any remaining water to drain out.
  
  If you’re able to stop the water to the outdoor faucet, allow the bib to remain open until warmer temperatures in spring. This ensures that any water present in the pipe won’t expand and break it. If you’re unable to turn the water supply off, fit the bib with an insulated cover.

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  Swimming Pool and Water Sprinkler Lines – Before cold weather hits late in the fall, drain the water from your supply lines leading to the pool, sprinkler system or other item. Follow the manufacturer’s instructions for best results. Do not flush or fill the lines with automotive antifreeze.

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  Crawlspaces, Attics and Other Unheated Areas – Even if the pipes are in an insulated area, if there’s no heat, they could get cold enough to freeze and burst. Insulate pipes running through un-insulated or unheated areas, both hot and cold water pipes. (Hot water pipes can also freeze if they stand long enough in cold enough weather.) Make a habit of looking over your pipes every autumn to ensure the insulation in good shape.

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  Pipes Running Along Exterior Walls – Any air penetration in a wall, or a poorly insulated wall, leaves your plumbing lines vulnerable to freezing temperatures. Not only is this a hazard during winter weather, it also means higher heating and cooling bills due to air leaks and lack of insulation. So while insulating pipes in these areas makes good sense to prevent them from freezing, the wise choice is to seal and insulate the walls whenever possible. Expanding foam insulation is an excellent choice for sealing larger gaps or filling in around door and window framing. Other winterizing and weatherproofing measures will ensure you save energy while also protecting your water pipes.

When Frigid Temperatures Strike

Even in the coldest, most miserable weather, you can further protect your plumbing by taking a few additional steps. Even if you’re not home at the time, you can still protect your pipes.

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  Turn on your faucets. Probably the single most important preventative action during a subfreezing spell is to turn on a faucet – or one faucet per water line. It doesn’t have to be much: Even a slow trickle of water ensures the water remains flowing, and flowing water freezes with more difficulty.

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  Open Doors. Underneath kitchen and bathroom sinks, inside cabinets, the temperature can be much lower than in the room. Open up the doors to allow air to circulate. This also applies to bathroom doors or any room in which you have a faucet or water-filled appliance. Keep the doors open to help battle frozen plumbing lines.

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  Close up the garage. If you have water lines running through your garage, keeping the garage doors shut helps keep the temperature and wind chill higher.

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  Raise your thermostat. Keep your thermostat setting a little higher when the temperatures drop below freezing. If you normally lower the temperature at night, leave it at the daytime setting. If you have a high-efficiency home that’s super-insulated, this may not be necessary.

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  Prepare for an absence. If you will be away from home for an extended period of time, plan for your pipes. First, keep your thermostat set at a minimum of 55 degrees F. This will prevent the inside temperature from plummeting into the danger zone.

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  Ask someone you trust to visit daily. Have them flush the toilet, run a couple of faucets, and look around to ensure your pipes are fine.

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  Consider draining your water system. If you can’t have someone come by your house, this is another option. Shut off the water supply and drain the lines and fixtures. An empty pipe will not burst.

How Do I Turn Off My Water Supply?

Typically, residential water has two main water shut-off valves: The first, called a corporation stop, is underneath the street. You will find the second near the water meter. Depending on your location, this may be on the side of your home, buried in the ground near the street, in your basement, or another location readily accessible to you. You probably have other shut-offs on the lines leading to the fixture.

When Pipes Freeze

What you need to do to treat a frozen pipe varies depending on whether it’s simply frozen – a pain, but not a tragedy – or whether it burst and possibly caused water damage in your home. The sooner you recognize the problem and take action the better. A pipe with a 1/8-inch crack will spray up to 250 gallons in 24 hours, reports Goodfellow Air Force Base. At that point you don’t simply need a plumber to replace the plumbing, you also have a flood on your hands. Floors, walls, furniture, personal items – all can be destroyed in the process. Then there’s the mold that can quickly start to grow. While burst pipes make the problem obvious, if you’re lucky, you’ll find out before an eruption. You’ll turn on a faucet and nothing will flow. That’s when you’ll know a pipe’s frozen.

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  Turn off the water. If you can’t access your home’s water shut-off valve, call the local water company and ask for emergency service.

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  Open your faucets. Not only does this help relieve pressure in conjunction with shutting off the water source, it also gives soon-to-be-melted water a place to go. It also encourages the ice to melt.

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  Turn off your water heater. Allowing an empty water heater to run is damaging, and your water supply may be off for quite some time.

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  Start thawing your pipes. You have several options when it comes to thawing your plumbing lines. The only option you don’t have is to wait, doing nothing. Time is of the essence – the longer the ice sits undisturbed, the more likely the pipe will break, if it hasn’t already. Even if you’re dealing with a flood inside your home, you can work to melt the ice at the same time.

How to Thaw Frozen Water Pipes

Choose the methods that work best for you. If you try your faucet and it still appears clogged with ice, be patient. De-icing your water lines may take longer than you expect. Most important, never hurry the process by using unsafe methods. Open flames and extremely high temperatures such as blowtorches, charcoal stoves and kerosene or propane heaters are dangerous. Using them on frozen pipes may result in melting plastic pipes, boiling the water inside and causing an explosion, igniting fumes or worse. Also, to prevent shock, never stand in water while handling any electrical item.

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  Turn up the temperature. Raise the temperature inside your home. Open doors and use fans as necessary to direct warm air into the room or area containing the frozen pipe.

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  Use a space heater. Be especially cautious if using a space heater inside the home. Keep the heater at least 3 feet away from the pipe and any surrounding materials. Observe during use.

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  Wrap the frozen pipe with a heating pad. Use an electric model or use your imagination. A towel, heated in the microwave and wrapped around the pipe will work, as will towels soaked in hot water (just make sure you don’t allow it to freeze to the pipe).

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  Turn on the hair dryer. Directing the heat at the pipe from a distance of about 6 to 8 inches away. Give the hair dryer breaks to prevent overheating.

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  Use electric pipe heating tape. Available at home improvement stores, it will thaw the ice safely.

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  Call a plumber. Licensed plumbers have a special tool that melts the ice via an electrical charge.

Help! My Drain is Frozen!

If you’re dealing with a frozen drainpipe, try the same methods as those mentioned above. Alternatively, try pouring very hot water down the drainpipe. Do it slowly to prevent an overflow. A snake may knock the ice free in some instances. Goodfellow Air Force Base advises you can even attach a section of rubber tubing to a kettle’s spout, insert the other end into the drain, and allow water to boil, creating steam. The steam will gradually melt the ice. At least, that’s how the GIs do it!