It’s a law of physics: When water freezes, it expands. That’s why a can of soda (or pop if you prefer) explodes when put into a freezer to chill quickly and forgotten. When water freezes in a pipe, it expands in the same manner. If it expands enough, the pipe bursts, water escapes and can result in an expensive aftermath.
What’s worse than a major home maintenance disaster? Try several major home maintenance disasters all at one time. When a house’s water pipes freeze, the situation is not as simple as calling a plumber. A 1/8-inch crack in a pipe can spew up to 250 gallons of water a day, causing flooding, severe structural damage, and the immediate potential for mold.
Frozen pipes affect a quarter-million families each year, and it can happen in homes with both plastic and copper pipes.
The types of plastic or metal pipes most susceptible to freezing include outdoor hose bibs, swimming pool supply lines and sprinkler lines; however, indoor piping isn’t necessarily any safer.
Plumbing in unheated areas – basements, crawl spaces, attics, garages, exterior walls or even kitchen cabinets – aren’t well protected, and these pipes can cause the biggest headaches. Frozen pipes that have cracked not only need to be replaced but, as we just noted, if they burst, they can also result in severe water damage within hours of thawing out.
How do you know if a pipe is frozen?
The most common indicator of a frozen pipe is that a faucet will not flow or a toilet will not flush, but pipes can be frozen without these symptoms. If you have a pipe that freezes, proceed carefully because it’s actually when a pipe thaws that it usually bursts.
Why pipes burst in the winter
Surprisingly, ice forming in a pipe does not, by and large, cause a break where the ice blockage occurs. That’s because it’s not the outward expansion of ice against the pipe wall that causes the pipe to break. Rather, following a complete ice blockage in a pipe, continual 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 can eventually lead to pipe failure. Typically, the pipe bursts where little or no ice has formed. Upstream from the ice blockage, the water can always retreat towards its source, so there is no pressure build-up to cause a break. Water must freeze for an ice blockage to occur.
In fact, you might not even be aware that a pipe has burst as the water has turned to ice. Once the temperature starts to warm up and thawing begins, that’s when leaking, and flooding can occur.
The truth is, it usually takes more than cold temperatures to freeze a pipe. More typically you need really cold temperatures, and cold wind blowing on it. There’s a lot of forgiveness in a plumbing system. Just don’t say that to someone whose pipes burst.
That said, here are some precautions you can take to help prevent severe damage.
Before the really cold weather arrives
All outside water lines to pools and sprinkler systems should be completely drained in the fall, so there’s no moisture left inside to expand in freezing temperatures. It should go without saying, but never put antifreeze in outdoor water supply lines. Despite the promising sound of its name, this product will not prevent frozen pipes.
In fact, get rid of the hose. We mean it. While a frozen garden hose sounds like a minor glitch, it can trigger major problems with your plumbing. When your hose freezes, it puts pressure on internal plumbing and increases the possibility of a pipe bursting. Do yourself a favor and drain your hose, disconnect it from the spigot and store it away until the warmer weather returns. Also, make sure you cap off the spigot and insulate it to keep the cold air from entering your pipes from the outside.
Find your water’s main shut-off valve. You need to know where this is before anything goes wrong. In most homes, you have two choices: the main shutoff valve and the meter connection. The main valve is likely on an exterior wall near a faucet or inside your basement or utility room. Turning off the water at the meter, however, requires a water meter key, which you can find at most hardware stores. In either instance, confirm the location and visibly mark the shutoff before the start of colder weather.
Seal up cracks and holes. You should caulk any holes or cracks that exist near pipes. This should be done on both exterior and interior walls. Doing so can help keep the cold air out and the warm air in.Look for air leaks around electrical wiring, dryer vents, etc. with the severe cold; even a tiny opening can let in enough cold air to cause a pipe to freeze.
Insulate. Insulate. Insulate. Insulate pipes in your home’s crawl spaces and attic. Exposed pipes are most susceptible to freezing. Remember, the more insulation you use, the better protected your pipes will be. Often inexpensive foam pipe insulation is enough, but you might want to opt for wrapping especially problem pipes with thermostatically controlled heat tape which will turn on automatically when the temperature plunges. If you’re going to insulate, don’t leave blank spots, especially at elbows and T’s, where pipes can be more vulnerable to freezing. And make sure all the fittings are insulated as well. Even newspaper can provide some degree of insulation and protection to exposed pipes – a ¼-inch of newspaper can provide significant protection in areas that usually do not have frequent or prolonged temperatures below freezing. On the other hand, your crawlspace vents are okay to cover in the winter to keep the crawlspace warmer. You can cut sheets of foam insulation to shape or buy pre-made foam blocks. Just be sure to remove them when the weather warms as your crawlspace needs that air circulation to prevent mold.
Caution. Don’t try to warm your attic by blocking off your roof vents to retain heat. Especially when it snows, your attic needs this flow of cold air on the underside of the roof. It keeps the snow from melting too quickly which helps prevent ice dams. Instead, seal off the cold air leaks that your attic doesn’t need by following the guidelines in the EPA’s DIY guide to sealing and insulating.
If pipes in exterior walls have frozen in the past (tell-tale signs include water damage, mold, and moisture build-up), it’s probably because of insufficient or incorrectly installed insulation. It might be worth a couple of hundred dollars to open up the wall and beef up the insulation.
Do this when a hard freeze is expected.
Pay attention to the weather forecast. Most frozen pipes take place during intervals of extreme or prolonged cold temperatures. So, know when the thermometer is anticipated to dip in your area and take preventive measures. There’s no magic number on the thermometer to indicate frozen pipe conditions since wind chill factors, and shady areas can trigger conditions to be even colder than the temperature might suggest. It’s best to be on alert whenever temperatures drop well below 32 degrees.
Open cabinet doors beneath sinks. Remember the saying that an ounce of prevention is worth a pound of cure? Cabinet doors can prevent warm home air from circulating around the pipes beneath your sink. Prop the door open to keep pipes from freezing but make darn sure you don’t have poisonous cleaners or other dangerous items that children or pets can get into.
Keep the heat on. The heat in your home’s living space is critical in keeping your pipes from freezing. So, don’t try to save money by turning off the heat in unused spaces. And if you’re facing one of those polar vortexes, consider turning up your heat a few degrees for a little extra protection.
Allow the indoor faucets to drip. We know you’ve heard this before. And you might be thinking, “Does this really help?” the answer is yes! It’s not that a small flow of water prevents freezing; this helps, but water can freeze even with a slow flow. If a pipe freezes, as we’ve noted above, the reason it bursts is the pressure created between the blockage and the faucet. Keeping your water running at less than a trickle helps lessen the risk of pressure build-up during periods of freezing temperatures. Even the slowest drip at normal pressure will provide pressure relief when needed. Where both hot and cold lines serve a spigot, make sure each one contributes to the drip, since both are subject to freezing.
Going away for an extended period?
If you’re leaving for an extended period of time, make sure you leave the heat on. This can sound like a tall order, give the high cost of home heating, but the heat can help prevent frozen pipes. Remember, if pipes freeze and burst, the damage to your property and possessions will certainly trump a high heating bill.
As a rule of thumb, keep your home’s thermostat set at 55 degrees or above, even if you’re away. Moreover, if gone for an extended period, ask a trusted person to check on your home and pipes while you’re gone.
What do I do if the pipe freezes?
If you turn on a faucet and only a trickle comes out, suspect a frozen pipe. Likely places include exterior walls or where your water service enters your home through the foundation.
Steps to take when your pipes have frozen:
First step: Don’t panic. Just because they’re frozen doesn’t mean they’ve already burst.
Step two: Open every faucet to see which, if any, produces a trickle of water. Starting at the plumbing nearest the faucet, follow the line away from it and feel every few feet to find the coldest pipes, which most likely hold the ice blockage. Remember, if one pipe has frozen, others may be susceptible as well. Check all the faucets in your home.
Step three: Shut off the water to the location of the frozen pipe (or even the whole house) by turning it clockwise to its “off position. When the blockage thaws, it may let out any additional water backed up behind it and turn up a surprise leak, so have a bucket, towels and perhaps a mop handy for any icy water that gushes out.
Step four: Drain all the remaining water in the house by opening every faucet on every sink, shower, and tub and flushing each toilet twice.
Step five: Heat things up. Apply heat to the frozen sections of pipe using an electric heating pad, a hair dryer or a portable space heater until full water pressure is restored. Warm the edge of the area closest to the nearest outlet in the plumbing – like in the kitchen or bathroom – so that steam or water can easily escape. A space heater (or, if you have zoned heating, an adjustment of the nearest thermostat) could also do the trick to concentrate warmth wherever needed.
WARNING: Whatever you do, never use a blowtorch, propane heater or other open flames.
Okay, now that we’ve given you some tips on how best to prevent your pipes from freezing as well as additional suggestions on how to un-freeze them, our advice would be to give us a call if and when you run into trouble!