Frozen pipe burst — why it happens and how to prevent it in NJ winters
A practical guide to preventing the single most expensive cold-weather property loss. What to do before, during, and after a freeze event.
Frozen pipe bursts are the single most common cold-weather property loss we handle in NJ. The setup: a sub-freezing snap (typically 3+ days of overnight temperatures below 20°F), a pipe in an unheated or poorly-insulated space, and a homeowner who does not realize until the thaw that water has been flowing through the burst all night. Average loss: $5,000-$30,000 depending on what got wet and how long.
Why pipes burst
Water expands ~9% when it freezes. A pipe full of water that freezes expands beyond what the pipe can contain — the pipe ruptures, often at a fitting or solder joint where the wall is thinnest. The rupture itself does not flood the property — there is ice in the pipe, blocking flow. The flooding starts AFTER the thaw, when liquid water flows through the rupture.
The most vulnerable NJ pipes: supply lines in unheated garages, attics, crawlspaces, exterior walls (especially north-facing), and vacant properties where the heat has been turned down. Hose bibs (outside spigots) and the supply lines feeding them are the single most common burst location.
Prevention before the freeze
- Insulate exposed supply lines. Foam pipe insulation from any home center costs ~$1/ft. Wrap any supply line in an unheated space, especially exterior walls.
- Drip the faucets during sub-freezing nights. Slow flow keeps water moving through the line, prevents ice formation. Cold-side faucets only. Hot-side does not need to drip because hot water lines are typically interior.
- Disconnect garden hoses from outside hose bibs. A hose left attached creates a closed system that traps water in the supply line, where it can freeze and rupture the pipe inside the wall.
- Open cabinet doors under sinks on exterior walls. Lets warm room air reach the supply lines.
- Keep the heat on if you travel. Set the thermostat to 55°F minimum. Turning the heat off entirely to save money during a cold snap is the most common cause of vacant-property bursts.
If you suspect a frozen pipe (no flow at a fixture)
Open the affected fixture (hot AND cold side) so when the pipe thaws, water has a path out without pressure building up. Locate the frozen section if possible (often visibly cold or with frost on it). Apply gentle heat — hair dryer, heat lamp, warm towels. Do NOT use open flame or high-heat torches; these can damage pipes or start fires. Start at the open faucet and work back toward the frozen section so as ice melts it can drain.
If a pipe has already burst
Shut off the water at the main immediately. If the water is reaching outlets or fixtures, kill power to the affected area at the breaker. Move what you can save away from the cascade path. Photograph everything for insurance. Then call us — our structural drying service protocol on burst-pipe calls dispatches with extraction equipment and structural drying gear within the hour. The faster we get to your Newark property, the less material has to come out.
For vacant properties
If you own a NJ vacation home or rental property that sits vacant during cold months, the prevention measures above are even more important — there is no one in the property to notice a burst until the thaw, by which point significant water has flowed. Consider winterization (drain the entire system) for properties that will be vacant more than 30 days during freeze season. We handle structural rebuild after burst events at vacant properties regularly — coordinating with absentee owners through email + photos rather than in-person visits.