Pipes typically burst when exposed to extremely low temperatures for an extended period of time (anywhere from 1-3 days depending on temperature). This is especially true for pipes located on exterior walls.
Although common, frozen pipes do not always burst. However, the ice can increase this risk when it thaws and is usually worsened as it raises pressure further which makes pipe bursting common near winter's end or springtime. Furthermore, the more water flowing through the pipe, the greater chance of rupture.
And once the temperature outside dips below 32F, unprotected pipes are at a greater risk of freezing and potentially bursting. That said, it's still possible for your pipes to thaw without bursting. The key is to release the pressure and allow the pipes to thaw slowly.
However, the time it will take for them to burst depends on just how cold it is and for how long. A quick cold snap isn't likely to make them burst, but if temperatures are very low for more than four to six hours, your pipes can burst.
If your pipes have been frozen for more than two days, shut down your home's water supply. Locate the frozen length using touch, sight and sound. Make sure the pipe hasn't burst, and open indoor faucets. Unfreeze the pipe using a hair dryer, heat tape, space heater or heating pad.
The job goes more quickly by pouring hot water or a mixture of vinegar, baking soda and salt water down the drain. Space heaters, hair dryers and heating pads are highly efficient tools for unfreezing a drain pipe. If a frozen drain line ruptures, turn off your home's main water supply.
If you are unable to locate the frozen area, if the frozen area is not accessible, or if you can not thaw the pipe, call a licensed plumber.
Prevent Frozen Pipes
Moving water keeps pipes from freezing. Find shut off valves for emergencies. Insulate pipes in unheated areas. Open cupboards and vanities to warm pipes.
However, both PVC and CPVC (think of them as coming from the same family of plastic pipes) are brittle and will crack at low temperatures. So, while not the worse solution, they are still vulnerable to freezing conditions.
Thawing Frozen Pipes
While you wait, reduce water pressure by opening all the faucets inside the home one-quarter turn. Water will begin to trickle out, helping the ice to thaw. Remember to close all faucets after full water pressure is restored.
Turn on all faucets: Checking each faucet in your home will help you narrow down your search. The faucets that have little or no water pressure likely have a frozen pipe in their supply line. If every faucet is showing low water pressure, the frozen pipe may be near the water meter.
Yes, pipes can freeze overnight if temperatures plummet drastically. Uninsulated pipes in unheated areas like attics or exterior walls are most vulnerable.
Technically yes, but the “wait-and-watch” method carries risk. As that ice begins to thaw, any water caught between the faucet and the ice will cause increased pressure within the pipe. That increase in pressure can lead to frozen pipes bursting.
The pipes most likely to freeze are those nearest to an uninsulated wall, door, window, garage, attic, basement, or along an uninsulated floor. Add insulation to exterior walls wherever possible and wrap pipes with insulation. Eliminate cold drafts near water pipes and your water meter.
This finding was supported by a survey of 71 plumbers practic- ing in southern states, in which the consensus was that burst- pipe problems began to appear when temperatures fell into the teens. However, freezing incidents can occur when the tem- perature remains above 20 degrees F.
Lagging or insulating your pipes with cheap foam tubing is simple and can help prevent your pipes from freezing.
DURING freezing weather:
If you plan to be away from home for several days, shutting off the water can reduce the chances of broken pipes. Set your home heat to at least 55 degrees. Shut off water to the house and open all faucets to drain pipes; flush the toilet once to drain the tank, but not the bowl.
Overall, it's best that you take heed and drip your faucets when temperatures dip below freezing. A simple trickle of hot and/or cold water—both from faucets inside and outside the home—can prevent you from having to deal with a much larger issue (and bill!) in the long run.
Frozen pipes can cut off your home's water supply and cause damaging leaks. In many cases, the help of a plumber is needed to resolve the problem. To prevent further damage, it is generally recommended that you turn off your main water supply valve and your water heater until repairs have been made.
Contact a professional plumber equipped with pipe-thawing equipment to get your pipes flowing again and, if necessary, repair damaged pipes. Even if you see no evidence of leaks, plumbers should examine pipes that experienced a hard freeze.
In general, you should let at least one faucet drip in each section of your home.
We don't recommend the waiting game because the longer your pipes are frozen the more likely it is that they could burst. Burst pipes lead to water damage and water damage may result in structural and property damage, not to mention mold growth.