Ice storms in this region can cut the power, let pipes freeze and then leak on the thaw. The months when the risk is highest run from the first hard freeze in winter through the first warm spell. This guide sets out the calendar, the shut-off and the checks to make on each stage.
Key takeaways
- Know where the main shut-off is before the first freeze, and check that it turns
- The leak often shows on the thaw, not in the cold, so check the walls and ceilings after the warm-up
- A house without heat for a night can split a line even when the temperature inside seems fine
- Keep the heat on at a safe setting and never use an open flame to thaw a pipe
- Insulate exposed lines and fit heat tape where a plumber advises
- After an ice storm, check the attic and the crawl space as well as the rooms
What does the winter calendar look like?
Risk builds with the first hard freeze and peaks during and just after an ice storm. The table sets out what to do in each part of the season, so the checks happen before the cold rather than after the leak.
The table is a guide, not a forecast. Weather in the region can change quickly, and an ice storm can arrive in the middle of a warm spell. The safe habit is to do the autumn checks, then to watch the forecast and act when a freeze is announced.
The months when a leak is most often found are the ones after the thaw, when the house warms and the water in the split line starts to move.
| When | What to check | What to do if it fails |
|---|---|---|
| Late autumn | The main shut-off turns, the outside taps are drained, and the insulation on exposed lines is in place | Replace worn insulation and have a plumber fit heat tape to the most exposed line |
| Before a forecast freeze | Heat is set to a safe level, cabinet doors under sinks are open on the coldest nights, and a torch is to hand | Let taps drip on the coldest nights if a line is at risk, and keep the house warm |
| During an ice storm | The power, the heat and the water pressure at the taps | Shut the main if a line splits; keep the generator outside if one is used |
| First warm day after the freeze | Ceilings, walls near outside corners, the crawl space access and the meter with every fixture off | Call a plumber for any split line and the crew for the water that came out |
| The following weeks | Stains that grow, soft boards and damp at the base of walls | Record the date and the place, then call; slow leaks show late |
Where do pipes split in a house like this?
Pipes split where they are coldest and least protected: in outside walls, in crawl spaces, under the house and in unheated rooms. The split is often at a joint or a bend, not along the length of the pipe.
A line in an outside wall is the most common case. The wall is cold on one side, and the water inside the pipe has nowhere to expand. A line under the house can freeze when the crawl space air drops below freezing, which happens in a long cold spell.
Water heaters, outside taps and any fitting that is not insulated are also at risk. A plumber can tell you which ones need attention in your house.
What should you do on the day of the freeze?
Keep the heat on, know where the main is, and check the house for signs of a leak as the temperature rises. If the power goes out for a long time, drain the lines you can reach while the water still runs.
If the house is cold and the power is off, the main should be shut before the thaw. A line that is split under pressure keeps running after the freeze, so the main is the first thing to close.
Do not use a space heater near water, do not run a generator inside, and do not use a torch on a pipe. Those are the most common causes of injuries and fires after a freeze.
What happens on the thaw?
The water that was held in a split line starts to move as the pipe warms, and it reaches the wall or the floor below. The first sign is often a damp patch, a stain, a soft board or the sound of running water in a wall.
Walk the house on the first warm day. Check the ceilings below the upstairs bathrooms and the laundry, the walls near the outside corners and the crawl space access. Turn on a tap slowly and watch the meter.
If you find water, shut the main and call. If the water has already run and stopped, photograph the marks and keep the dates. The drying is planned from those marks.
After an ice storm: what else to check
Ice on the roof can leak into the attic and the ceilings days after the storm. Check the attic for wet insulation and staining, and the ceilings for drips or soft drywall.
The ice can also damage gutters, downspouts and the eaves, which lets water run down the walls. Look at those from the ground, and do not climb onto an iced roof.
A roofer should look at any roof leak. The restoration crew dries and records the damage inside the house, and the two visits can work from the same plan.
When to call, and what to say
Call at once if water is coming through a ceiling or a wall, if a line has split and cannot be shut off, or if the house has lost heat and the water is at risk. Give the address, the floor and whether water is still running.
The line is answered 24/7, and a crew is sent as soon as one is free. In a storm the wait can be longer, and the first steps given on the phone are the most useful thing you can do while you wait.
A split line is a plumber's repair, and the crew will say so in the scope. Ask the plumber for the repair in writing, and keep the invoice with the restoration record.
Which houses are most exposed to a freeze?
Houses with lines in outside walls, crawl spaces, unheated garages and utility rooms are the most exposed. Older houses with no insulation on the lines and houses that are empty for a time are at higher risk.
A line that runs along an outside wall has no protection from the wind. Lines in unheated garages and utility rooms freeze when the heat is off, and a house left empty while the heat is low can freeze all its lines within a single cold night.
A plumber can show you which lines are most exposed in your house. Insulating those lines and fitting heat tape where a plumber advises reduces the risk more than any other single step.
What should a homeowner do before a cold spell is forecast?
Check the heat, the insulation and the shut-off. Set the thermostat to a safe level for the whole house, not just the rooms in use, and open the cabinet doors under sinks on exposed walls.
A house that is heated only in the rooms in use will let the outside walls and the crawl space fall below freezing. Keep the heat on across the whole house during a cold spell, and keep the air moving to the lines in the walls.
Let a tap drip during a hard freeze if a line is at risk. The water movement stops the pipe freezing solid, and the small cost of the water is far less than the cost of a split line. Keep the tap running slowly, and close it once the cold has passed.
What should happen after a split line is found?
Shut the main, drain the line if you can, call a plumber for the repair and call the restoration crew for the water that came out. The two jobs are separate, but they should be planned together so the drying and the repair do not get in each other's way.
The plumber repairs the split and tests the line before the water is turned back on. The restoration crew dries the water that came out and records the path. The crew should not close the wall until the plumber has finished, and the plumber should not close it until the crew has signed off the readings.
Keep the plumber's invoice, the crew's log and the photographs of the split together. The insurer will want all three, and a future buyer may want the same history.
What to do if the power is out for days
A long power cut is the most dangerous kind of freeze, because the house cools steadily and the lines can freeze in many places. Plan for it by knowing where the main is, draining the lines you can reach and keeping the house above freezing where it is safe to do so.
If the power is out for more than a day, drain the lines that are most exposed, such as the outside taps and the lines in the crawl space, if you can reach them safely. Open the taps at the lowest point of the house, and leave them open until the power is back and the heat is restored.
Do not use a gas oven or a camp stove to heat the house. Those release carbon monoxide in a closed room. A generator must run outside and well away from openings, and a carbon monoxide alarm should be in place in any room the exhaust could reach.
Frequently asked questions
Should I let the taps drip during a freeze?
Letting a tap drip can help keep a line from freezing during a very cold spell, especially one on an outside wall. It is not a substitute for heat or insulation.
Why did the leak start a day after the power came back?
The water in a split line can stay still while the pipe is frozen, and it begins to leak when the ice melts and the pressure returns. The split may have happened days before.
Can I thaw a pipe with a hair dryer?
Gently, on the exposed section, with the water running slowly to the open tap. Never use an open flame, and call a plumber if the pipe is inside a wall.
What if I cannot find the main?
Ask a plumber to show you before the next freeze. Until you know where it is, close the valves on the fixtures nearest the leak and call.
Will the insurer cover a frozen pipe?
Many standard policies cover sudden damage from a burst pipe, but some exclude damage from freezing when the heat was off. Read the policy and ask in writing.
Is a generator safe to run during an ice storm?
Only outside, well away from doors and windows, with a carbon monoxide alarm in the house. Never run one in a garage or a basement.
Can a frozen pipe split if it is not leaking?
Yes. A pipe can split while still frozen, and the leak appears only when the ice melts. That is why the thaw check matters.
Do I need to call a plumber after every cold spell?
Not after every one, but call if a line has frozen, if the water pressure has dropped or if you find any sign of a leak on the thaw. A plumber can check the most exposed lines before the next winter.
Sources
- National Weather Service, Greenville-Spartanburg office
- U.S. Census Bureau QuickFacts, city of Asheville
- North Carolina Department of Insurance
This guide is general information for Buncombe County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.