Freeze and thaw is the winter pattern for homes in Brockton, and the damage often shows on the thaw rather than during the cold. A house that has lost heat for a night can split a line that leaks days later. This guide sets out the calendar, the shut-off and the checks for each stage of the season.
Key takeaways
- Know where the main shut-off is, and check that it turns, before the first freeze
- The leak often shows on the thaw, so check the walls and ceilings after the first mild spell
- A house without heat for a night can split a line even when the inside air seems mild
- 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 a cold spell, check the cellar and the lowest rooms as well as the upstairs
What does the winter calendar look like?
Risk builds with the first hard freeze and peaks during and just after a cold spell or a storm that cuts the power. The table sets out what to do in each part of the season, so the checks happen before the cold.
The table is a guide, not a forecast. Weather can change quickly, and a cold spell can arrive in the middle of a mild period. The safe habit is to do the autumn checks, then to watch the forecast and act when a freeze is announced.
The times a leak is most often found are the first mild days after a freeze, when the house warms and the water in a split line begins to move.
| When | What to check | What to do if it fails |
|---|---|---|
| Late autumn | The main shut-off turns, outside taps are drained, and 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 on outside walls 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 a cold spell or outage | Heat, water pressure and any sign of a drip at the taps | Shut the main if a line splits; keep any generator outside |
| First mild day after the freeze | Ceilings, walls near outside corners, the cellar access and the meter with every fixture off | Call a plumber for any split line and the crew for 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, because slow leaks show late |
Where do pipes split in a house like these?
Pipes split where they are coldest and least protected: in outside walls, in unheated garages and cellars, under the house and in rooms that are kept cool. 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 has nowhere to expand. A line in a cold cellar corner or a garage can freeze when the heat is off for a long time.
Outside taps, water heaters 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 I do on the day of a freeze?
Keep the heat on across the whole house, know where the main is and check 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 injury and fire after a freeze.
What happens on the thaw?
The water 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 inside a wall.
Walk the house on the first mild day. Check the ceilings below the upstairs bathrooms and the laundry, the walls near outside corners and the cellar 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, because the drying is planned from those marks.
When should I call, and what should I 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 cold snap or an outage 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 scope will say so. Ask the plumber for the repair in writing, and keep the invoice with the restoration record.
Keeping the house warm enough during a long cold spell
A house that is heated only in the rooms in use lets the outside walls and the cellar fall below freezing. Keep the heat on across the whole house and keep the air moving to the lines inside the walls.
Open the cabinet doors under sinks on outside walls and keep the cellar door closed to hold warmth in the rest of the house. On the coldest nights let the taps on the most exposed line drip slightly, because moving water is harder to freeze than still water.
If the house will be empty during a cold spell, drain the lines you can reach, leave the heat on at a low safe setting and ask a neighbour to check the house on the way past. A house left cold and empty is the most common setting for a split line.
Which lines to protect first
Protect the lines that are most exposed and most costly to repair: lines in outside walls, lines in garages and cellars, and lines that run near the foundation. A plumber can rank them for the house.
Insulate the exposed runs with foam sleeves, seal the gaps where cold air reaches the pipe and fit heat tape where a plumber advises. The cost of those steps is small compared with the cost of drying a wall that has soaked for days.
Check the insulation after each storm and each cold spell, because wind and wet can move it. A sleeve that has slipped off a bend leaves that bend as exposed as before.
What to check after the power comes back
After an outage, check the water heater, the boiler and the lines before the heat is turned up fully. A line that froze during the outage can leak as the house warms, and a heater that was off may need checking before it is restarted.
Restore the heat gradually, and check the lowest rooms and the cellar for water as the temperature rises. Look at the meter with every fixture off, and listen for running water in the walls.
If the heater or the boiler was off for a long time, ask a plumber to check it before it runs at full power. A checked system is far less likely to fail on the first cold night after the outage.
Choosing a plumber for a winter repair
Choose a plumber who is licensed for the work, who gives a written estimate and who will explain the repair and the test. Ask whether the plumber will put the repair in the same record as the drying.
A plumber who explains the split and the repair clearly is easier to check than one who gives only a total. Ask for the part that failed, the reason it failed and what will stop the same failure next winter.
The test before the wall is closed is the most important step. Ask the plumber to run the line at full pressure and to note the result on the invoice, so the restoration crew can close its record against a tested line.
Frequently asked questions
Should I let the taps drip during a freeze?
Letting a tap drip can help keep a line from freezing in 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.
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 in a 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 cellar.
Should I call a plumber before every cold spell?
Not before every one, but a plumber should check the most exposed lines once a year, and call after any freeze that left a line cold for a long time.
Sources
- National Weather Service, Boston and Norton office
- Massachusetts Division of Insurance
- U.S. Census Bureau QuickFacts, city of Brockton
This guide is general information for Plymouth County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.