Frozen pipes are inconvenient. Burst pipes can do a lot of damage. Minimize the risk to your plumbing and learn how to thaw pipes and make temporary repairs.
Water expands when it freezes. In pipes, the expansion can cause ruptures. The damage often occurs not at the point where a pipe has frozen, but between the freeze and a faucet. As the ice blocks the pipe completely and expands, the water pressure in the pipe increases. Too much pressure will rupture the pipe.
In northern regions of the United States, pipes are typically protected in insulated spaces, reducing the risk of freezing. In southern climates, where subfreezing temperatures are less common, pipes may not be as well protected. Pipes that run through exterior walls are particularly at risk, but those that run through uninsulated attics and crawlspaces can also freeze. In either region, extended subfreezing weather, cracks in walls or foundations and entry points for pipe and cable put pipes at risk. Poor insulation increases the vulnerability. Outside the home, hose spigots are also at risk.
When temperatures drop below freezing, unprotected pipes can freeze from a combination of exposure, wind chill and the duration of subfreezing weather. In southern climates, where the risk of frozen pipes is highest, temperatures of 20° F or below present the greatest threat to pipes in unheated areas of the home.
Many of the repairs and improvements you can make to minimize the risk of frozen pipes are basic energy-conservation practices.
If you need help making improvements to prevent frozen pipes, contact a licensed builder or plumber. You may even be able to have the plumber move exposed pipes to areas that are less likely to freeze.
Check your insurance policy to see if it covers flooding from ruptured pipes.
If you don't have much time to prepare, there are still steps you can take to protect your pipes. Whether or not you've made the improvements listed above, these measures help reduce the risk from subfreezing temperatures:
There may be other areas around your home that need attention. Irrigation systems, swimming pool supply lines and devices in unheated garages — such as washing machines, water softeners and pressure washers — are at risk. Follow the manufacturers' instructions for winterization.
Once subfreezing weather arrives, check the water flow periodically. If you notice a drop in water pressure, it might be a signal that the pipes are beginning to freeze. Leave the faucets open to keep the water flowing and to relieve pressure.
Despite your preparation, you may still have to deal with frozen pipes. If they freeze:
Leave the affected faucets open and turn off the water supply.
If possible, locate the freeze point. Determine which faucets are not delivering water and check the pipes that supply them. If none of the faucets in the home are working, the freeze point may be in the main supply line. Check areas where supply lines enter your home. Once you've located the frozen section of pipe, you may be able to find the exact freeze point (one part of the pipe feels colder than the surrounding pipe or part of the pipe has frost on it).
If you can't locate the freeze point, if it's inaccessible or you're not comfortable attempting to thaw the pipe, contact a licensed plumber.
Check to see if the pipe has burst before attempting to thaw it. If it has, turn off the water supply and repair the pipe before you thaw it.
If the pipe hasn't burst, you can attempt to thaw it by exposing it to heat, working toward the water supply from the faucet end of the freeze. There are several methods:
Continue thawing until you have full water pressure.
If the pipe begins leaking as you're thawing it, stop and turn off the water supply. If the leak is near electrical fittings or cables, turn off power to the area. Repair the pipe before continuing.
Don't use an open flame or any device that generates flames to thaw pipes. Don't use electrical devices in a wet area or if you are wet. Don't use them if the pipe is near a gas line. Use only GFCI outlets with electric devices. Don't heat the pipes too quickly and don't heat them to the point that they're too hot to touch or that the water in them boils.
Once you've thawed the pipes, dry and insulate them to protect against future freezing.
If your water meter is frozen, contact your water utility.
When a pipe ruptures, act quickly to prevent as much water damage as possible. You may be able to make temporary repairs to the pipe until you can get professional help from a plumber.
A leak detector connected to a home management system can alert you to problems in remote areas of the house.
If the rupture is near electrical fittings or cables, turn off power to the area.
Turn off the water supply.
If hot water is leaking from the pipe, turn off the supply valve coming from the water heater.
If your pipes aren't frozen, open the faucets to drain the water. If the burst pipe is frozen, make repairs before you attempt to thaw it.
If you need to drain the water from your pipes, first turn off your water heater according to the manufacturer's instructions.
Call a licensed plumber to replace the ruptured pipe.
Follow the steps above to minimize the risk of the pipes freezing again.