How to Winterize Pipes: Preventing Burst Pipes in Cold Weather
A burst pipe can release hundreds of gallons into your home before you shut off the water. Winterizing takes 1–2 hours and costs under $50 in materials. Here's the complete procedure for occupied homes, vacant properties, and vacation homes.
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Which pipes are at risk
Pipes freeze when the water inside drops to 32°F. The pipes most vulnerable are those with the least insulation and most exposure:
- Exterior walls: Pipes running inside exterior walls (especially north-facing) are the most common freeze point. Kitchen and bathroom pipes on outside walls are highest risk.
- Crawlspaces: Uninsulated crawlspaces can reach well below freezing in prolonged cold snaps. Any supply pipe running through one is at risk.
- Garages: Pipes in unheated garages — especially in homes where the garage is attached and has water supply for a utility sink.
- Outdoor spigots (hose bibs): Pipes connecting to outdoor spigots run through the exterior wall and are the most common residential freeze damage point.
- Attic runs: Less common, but homes in warmer climates sometimes have supply lines run through attic space — these are extremely vulnerable in unusual cold snaps.
Winterizing an occupied home
Outdoor spigots
Find the interior shutoff for each outdoor spigot (usually in the basement or crawlspace, on the supply pipe leading to that bib). Close the interior shutoff. Go outside and open the spigot fully to drain remaining water from the pipe. Leave the outdoor spigot open slightly — if the interior valve wasn't fully shut, the open faucet will drain pressure instead of building it. Install insulated spigot covers ($5–10 each).
Exposed pipes in crawlspaces and garages
Pipe insulation foam ($10–20 for a 6-foot section) slides over exposed pipes and provides meaningful protection down to around 20°F. For temperatures below that, add electrical heat tape ($20–60) over the foam — it has a thermostat that activates when temperature drops near freezing. Don't rely on foam alone for pipes in unheated garages in cold climates.
During extreme cold (<10°F)
Keep cabinet doors under kitchen and bathroom sinks open so warm air from the room reaches the pipes inside the cabinet. Let a thin trickle run from faucets on exterior walls — moving water doesn't freeze as easily as standing water. Keep the thermostat above 55°F even when you're away. The cost of a slightly higher heating bill is trivial versus the cost of burst pipe damage.
What NOT to do
Don't use an open flame (torch, heat gun, hair dryer directed at plastic pipe) to thaw a frozen pipe — PVC and CPVC will deform. Don't pour boiling water on a frozen pipe — thermal shock can crack it. Thaw slowly with a hair dryer on low starting from the faucet end toward the ice blockage. Keep the faucet open so steam and water can escape.
Winterizing a vacant or vacation property
A vacant home can't rely on ambient heat to protect pipes. Full drain-down is the only reliable protection:
- Shut off the main water supply.
- Open every faucet — hot and cold — throughout the house to drain supply lines. Start at the top floor and work down.
- Flush all toilets and hold the handle to drain the tank completely.
- Pour RV antifreeze ($5–8/gallon, non-toxic propylene glycol) into every drain trap — P-traps, toilet bowls, floor drains, and the trap in the washing machine. This keeps sewer gas out even without water in the trap.
- Drain the water heater: turn it off, connect a hose to the drain valve, run it to a drain.
- Have a neighbor check the property during extended cold periods.
As an Amazon Associate we earn from qualifying purchases.
As an Amazon Associate we earn from qualifying purchases.
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