Frozen Pipes: How to Prevent, Detect, and Thaw Them Safely
Frozen pipes can burst and cause thousands in water damage. Here is how to prevent them, spot the signs, and thaw them safely.
How Pipes Freeze and Burst
When water inside a pipe freezes, it expands by about 9 percent. This expansion creates enormous pressure between the ice blockage and the closed faucet, eventually splitting the pipe. The burst does not happen at the frozen section — it happens between the ice and the faucet where pressure builds. Pipes most at risk include those in unheated areas like garages, crawl spaces, and attics; pipes running along exterior walls; and outdoor hose bibs.
Prevention: Before Cold Weather Hits
Disconnect and drain all outdoor hoses. Shut off the water supply to outdoor faucets if you have separate indoor shut-off valves. Insulate exposed pipes in unheated areas with foam pipe insulation sleeves (about 3 dollars for 6 feet at any hardware store). Seal gaps and cracks in exterior walls near pipes to block cold air. If pipes run through cabinets on exterior walls, open the cabinet doors during extreme cold to let warm air reach the pipes.
Signs Your Pipes Are Frozen
No water or only a trickle comes out when you turn on a faucet. Frost visible on an exposed pipe. A bulge or crack visible on a pipe. Strange smells from drains (ice blockage can push sewer gases back up). If you notice any of these signs, act quickly — the pipe has not burst yet but it will if the ice continues to expand.
How to Thaw Safely
Open the faucet that the frozen pipe feeds. As you thaw the pipe, water needs somewhere to go and running water through the pipe helps melt the ice. Apply gentle heat to the frozen section using a hair dryer, heat lamp, space heater pointed at the area, or towels soaked in hot water wrapped around the pipe. Start at the faucet end and work toward the frozen section. Never use an open flame, blowtorch, or propane heater to thaw pipes as this can cause a fire or crack the pipe from thermal shock.
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