How do you keep pipes from freezing before a hard freeze?
Pipes freeze when water sits still in a line that is exposed to cold air for hours. Keeping them from freezing comes down to four things you can do the evening before: let the faucets on outside walls drip, open the cabinet doors under sinks so house heat reaches the pipes, cover or wrap any line running through a crawlspace or garage, and know exactly where your main water shutoff is before you need it.
Hard freezes are not an every-week event here, which is exactly why they catch people out. Most winters bring at least one night that drops well below freezing and stays there, and the Christmas 2022 freeze burst pipes across Jefferson County. A lot of homes around Birmingham were built with supply lines in crawlspaces and exterior walls that were never meant to sit in sustained cold, so a single bad night can do real damage.
Posted Nov 2, 2026. All posts
Watch the forecast, not the thermometer
A quick dip to 31 degrees for an hour before sunrise rarely hurts anything. The nights to worry about are the ones where temperatures fall into the low 20s or teens and stay below freezing for most of the night, especially with wind. The National Weather Service office in Birmingham issues hard freeze warnings a day or two ahead, and that warning is your cue to run through the list below while it is still daylight.
If you are going to be away, the warning matters even more. An empty house with the thermostat turned down is a classic setup for a burst line that runs for hours before anyone notices.
The night-before checklist
Start outside and work your way in.
Disconnect garden hoses from every outdoor spigot. A hose left attached traps water in the spigot body, and that is where the freeze starts. If you have foam covers for the hose bibs, put them on now.
Next, go under the house if you have a crawlspace. Look for supply lines running along the floor joists near the foundation vents. Close any vents you opened for summer and wrap exposed pipes with foam pipe sleeves or even old towels held with tape. Older homes often have long runs under the floor with no insulation at all.
Inside, open the cabinet doors under the kitchen and bathroom sinks, particularly any sink on an exterior wall. Pick the faucet farthest from where the water enters the house and let it drip from both hot and cold. A thin, steady drip is enough; the point is to keep water moving, not to fill the drain.
Finally, keep the thermostat set to a normal temperature overnight, at least the mid-60s, even if you usually let it fall. The few dollars of heat cost far less than a ceiling repair.
Find your main shutoff now, not at 3 a.m.
Every homeowner should know where the main water shutoff is and be able to turn it. In many Birmingham-area houses it sits where the line enters the home, often in a crawlspace, a utility closet or a basement wall, and in some cases only the street-side valve at the meter box works reliably. Try turning it before the cold arrives. If the handle is seized or crumbles, that is worth knowing in daylight.
Keep a flashlight near it. If a pipe does split, shutting the water off within a few minutes is the difference between a wet floor and a gutted room.
If a pipe freezes anyway
If you turn on a tap in the morning and get a trickle or nothing, a line is probably frozen. Leave that faucet open, then warm the suspected section gently with a hair dryer, a space heater kept at a safe distance, or warm towels. Never use an open flame or a torch on a pipe.
Look and listen for leaks as it thaws. A split pipe often does not leak until the ice inside melts, which is why so many bursts are discovered mid-morning the day after the freeze. If you see water spreading, shut off the main and call a licensed plumber. They will want to know where the break is and whether the water is off. Our emergency plumbing page covers what to do while you wait.
For broader cold-weather prep around the house, the federal winter weather guide at Ready.gov is a sensible checklist to keep handy too.
After the freeze
Once temperatures climb back above freezing, take ten minutes to walk the house again. Check under sinks, look at ceilings below bathrooms, and go back under the crawlspace with a light to look for drips or wet insulation. Turn on each outdoor spigot briefly and watch for water coming from the wall rather than the spout, which is a sign the line inside split.
If you found pipes with no insulation this time, wrap them properly before the next cold front. A permanent fix costs very little compared with the damage one burst line can do, and it means the next hard freeze warning is just a reminder to drip the faucets.
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