Prevent frozen pipes by keeping your thermostat at 55∘ F or higher, letting a slow trickle run from faucets connected to exterior walls, and opening sink cabinet doors to allow warm air to circulate. Always disconnect outdoor hoses, and insulate exposed plumbing in unheated areas like garages or basements.
One such method is dripping your faucets. This keeps the water in your pipes moving, which helps prevent freezing. While an effective method, many homeowners wonder how cold it needs to be before they drip their faucets. The standard suggestion is to start dripping your faucets at 20 degrees Fahrenheit.
Water inside pipes begins to freeze when outdoor temperatures drop to 32°F (0∘C0 raised to the composed with power cap C𝟎∘𝑪). However, the actual danger threshold for your plumbing is 20°F (-6.7∘Cnegative 6.7 raised to the composed with power cap C−𝟔.𝟕∘𝑪). Exposed or uninsulated pipes running through unheated spaces can freeze and burst if temperatures stay at this level for several hours.
Leave a slow trickle or a steady drip (about one drop every 1 to 2 seconds) to keep pipes from freezing. In extremely severe conditions, a slightly faster stream the width of a pencil is recommended. Always let the cold water run, and use the faucet farthest from your main water meter for the best coverage.
To keep pipes from freezing, you should drip both hot and cold water. Hot water pipes are just as vulnerable to freezing as cold ones, and keeping both lines trickling ensures water is moving through the entire plumbing system, drastically reducing the risk of ice buildup.
You don't need to leave every faucet in your home dripping during a freeze. One or two is enough. Choose faucets that are most vulnerable to freezing, such as those on exterior walls, in unheated spaces like the garage or basement, or the one that's the farthest from your hot water heater.
Do not use a blowtorch, kerosene or propane heater, charcoal stove, or other open flame device.
Uninsulated exterior pipes can freeze in under six hours if the temperature is below 20 degrees. It takes at least 12 hours for unprotected pipes to freeze at 32 degrees.
Under normal conditions, pure water begins to freeze at 𝟑𝟐∘𝐅 (0∘C). However, in order for the actual physical transition into ice to occur, the surrounding temperature usually needs to drop slightly below 32∘F.
The Critical Temperature
However, the real danger zone begins when the wind chill drives temperatures down to 20°F (-6°C) or lower. If your home has plumbing located in unheated areas—such as basements, crawl spaces, garages, or exterior walls—you should prepare immediately when these conditions are forecast.
The time it takes for pipes to freeze depends on various factors, including pipe material, insulation, and exposure to cold air. On average, pipes can freeze within six to eight hours when temperatures stay at 20 degrees or lower. If pipes are poorly insulated or exposed to drafts, they may freeze even faster.
Even if you go out of town, keep your heat at 60°F or higher to prevent internal pipes from freezing. You should also try to maintain a constant temperature throughout the day. Many people turn their heat down at night to save money while they sleep.
As temps drop, the risk of having frozen pipes in your home increases. Typical high-risk areas for freezing include pipes within exterior walls, as well as exposed pipes that run through unheated or uninsulated areas such as attics or basements.
At 28°F, it typically takes 12 to 24 hours for water inside standard uninsulated pipes to freeze. However, the exact time depends heavily on your home's setup:
If your inside temperature starts getting very very low, then it's not a bad idea to turn off the main and open some faucets to let them drip out what's left in the pipes. But otherwise, don't worry about it.
Experts on Southern Living recommend dripping your faucets once the weather hits below 20 degrees, and advise dripping a small trickle, not a steady stream. It's also suggested to leave cabinet doors open, allowing air from the home heater to warm the faucets. Dripping your faucets is particularly important overnight.
It's such a simple thing, leaving a single faucet dripping, but it can prevent so many complications later on. How much value does one dripping faucet have? A lot, if it keeps your home's water pipes from bursting during frigid weather.
"Ponds and bird baths benefit, as a tennis ball floating on the surface moves with the wind and helps stop water freezing completely, which is vital as birds still need to drink and bathe in winter to keep their feathers in good condition."
It might seem clear that pipes freeze when temperatures drop below freezing, but it's more complex than that. Water freezes at 32°F, but pipes usually don't freeze unless the temperature dips to 20°F or lower. As mentioned earlier, pipes in unheated or uninsulated areas are the first to freeze.
Avoid burst pipes and stay safe in winter:
Keep the heating on overnight at a low temperature if you can. If you have no heating, turn your water off at night, if possible. This should minimise any damage if there is a thaw overnight. Make sure there are no draughts from outside, especially near water pipes.
When Should You Let Your Faucets Drip? It's a good idea to let faucets drip when the outside temperature falls below 32°F, particularly if you know that the cold will last for several hours or more.
The Freezing Point of Pipes
Freezing starts at just 32 degrees Fahrenheit. As such, it doesn't have to be excessively cold outdoors for plumbing problems to arise. However, in most cases, water at the interior of plumbing systems won't start icing over until temperatures reach as low as 20 degrees Fahrenheit.
Allow warm air to circulate in the area where the water comes in to the house. Leave utility room doors open and clear space around the water line to help prevent cold pockets of air near the pipes. Remove contents of vanity cupboards that conceal pipes, and leave the doors open.
Hair dryers can also be used to help thaw out pipes. Most hair dryers have a heat setting designed to quickly dry hair, but the heat is enough to slowly thaw a pipe as well. With frozen pipes, time is valuable, so it's important to thaw them as quickly as possible.
Rubbing alcohol does not technically "stop" water from freezing on its own, but it significantly lowers the freezing point of water through a process called freezing point depression.