Pipes usually split while they are frozen, when pressure builds between the ice and a closed faucet, but the ice holds the crack shut. The water only pours out when the ice melts and flow returns. That is why burst pipes show up a day or two after a deep freeze, on the first warm day. Water showing up after a cold snap? Call (413) 603-1274.
What actually happens inside the pipe
- Water in an exposed section freezes and forms an ice plug.
- The ice keeps growing, pushing water toward the closed faucet downstream.
- Pressure builds in the water trapped between the ice and the faucet.
- The pipe splits, often in that trapped section, not where the ice is.
- Nothing leaks yet, because the ice still blocks the flow.
- The weather warms, the ice melts, and water rushes out through the crack.
Chicopee examples
- February 2015: weeks of record cold drove the frost line deep. The Chicopee Water Department took over 100 frozen pipe calls in two weeks.
- February 2016: a weekend below 15°F, then the low 50s by Tuesday. As pipes thawed they burst, and the Chicopee Fire Department lent residents pumps and hoses.
- February 2023: 9 below in Chicopee, then 48°F two days later. Holyoke firefighters answered about 50 calls in one night, 28 of them burst pipes.
See the Chicopee freeze report for 30 winters of data.
What this means for you
- The day after a deep freeze, check basements, walls and ceilings before leaving for work
- If a pipe was frozen, thaw it under control with the main valve ready
- If you are away, shut the main before the warm-up
- Open faucets during the freeze so pressure has somewhere to go
Why the split is often not where the ice was
When a section of pipe freezes, the ice plug itself usually does not split the pipe. The danger is the water trapped between the ice and a closed faucet. As more ice forms, it pushes against that trapped water, and pressure in that short section climbs until the pipe gives way, often a foot or more from the ice. That is why you can thaw the frozen spot and still find a leak somewhere else on the line, and why opening the faucet before and during a freeze helps: it gives that pressure somewhere to go.
Check after every deep freeze
After a cold snap breaks, walk the basement, look under sinks on outside walls, check porch ceilings and the floor around the water heater, and read your meter with everything off. Catching a split in the first hour is the difference between a towel and a renovation.
Keep the faucet on a frozen line open while it thaws, so pressure can escape.
Questions
Can I tell if a frozen pipe has already cracked?
On exposed copper you may see a bulge or a split seam. Inside walls you usually cannot until it leaks. See how long before frozen pipes burst.
Does PEX burst too?
PEX stretches more than copper and resists splitting, but fittings and valves on PEX lines can still crack.
Water after the thaw? Call now
Call (413) 603-1274 now. Locally owned in Chicopee: we fix the pipe and dry the house in one call. Read the Chicopee frozen pipes guide.