Burst and frozen pipes

Last updated: 2026-07-18 · Reviewed by the DisasterStatus editorial team

A burst pipe releases hundreds of gallons an hour, and it doesn’t stop on its own. The difference between a nuisance and a gutted floor is usually measured in minutes — how fast the water goes off and how fast it comes back out. This guide covers three things in the order you’ll need them: what to do the moment a pipe bursts, how to thaw a frozen pipe before it splits, and how to keep pipes from freezing next winter. If you’re standing in water right now, skip straight to the first section.

What to do the moment a pipe bursts

Work these steps in order. The goal is simple: stop the water, make the area safe, and get every drop out before it soaks into materials that hold moisture — the subfloor, the drywall, the framing.

1. Shut off the main water supply. Find your home’s main shutoff valve — usually where the water line enters the house, near the meter, in a basement, crawl space, or utility closet — and turn it clockwise until it stops. This cuts water to the whole house and stops the flood at its source. Locating this valve before an emergency is the single best thing you can do; in a burst, every minute of running water is more damage.
2. Cut the power near the water. If water is near outlets, light fixtures, or your electrical panel, switch off the circuits to that area at the breaker — but only if you can reach the panel without standing in water. Never touch a breaker or a plugged-in appliance while standing in water. If you can’t reach the panel safely, stay out and call an electrician or your utility.
3. Open the faucets to drain the lines. With the main off, open the cold taps around the house and flush the toilets to drain the water still sitting in the pipes. This relieves pressure and empties the line feeding the break, so less water keeps pushing out onto your floors and into your walls.
4. Document the damage before you clean up. Photograph and video the burst pipe and every wet room, item, and surface before you move or remove anything. You have a duty to limit further damage, but a clear record of the original condition makes your insurance claim far stronger.
5. Get the water out fast — and call a pro. Start removing standing water immediately with a wet/dry vac, mop, and towels, and pull wet contents up off the floor. Wet materials should be dried within 24–48 hours to head off mold, so for anything beyond a small, contained leak, get a professional with extraction and drying equipment on the way while you work.

Speed matters because of what happens next. The EPA notes that wet materials must be dried within 24–48 hours to prevent mold, and a burst pipe can saturate a subfloor long before the surface looks wet. That’s why the smart move for anything past a small, contained leak is to get extraction and drying equipment on site fast. If the water is deep or still spreading, see emergency water removal — and when the job is beyond a shop vac, we can connect you with a vetted local water damage restoration pro, free and available 24/7. For the full recovery arc from here, our water damage cleanup guide walks through drying and repair, and if the water pooled downstairs, basement flood cleanup covers that specific job.

How to safely thaw a frozen pipe

A frozen pipe is a burst that hasn’t happened yet. When water freezes it expands, and it’s the pressure trapped between the ice and a closed faucet — not the ice itself — that splits the pipe. Thawing it promptly and gently is how you head that off. If you turn on a tap in a cold snap and only a trickle comes out, suspect a frozen line and act before it fails.

• Open the faucet that the frozen pipe supplies. As the ice melts, water and steam need somewhere to go, and running water through the pipe helps the thaw along.
• Apply gentle, steady heat to the frozen section — an electric heating pad wrapped around the pipe, a hair dryer, a portable space heater kept well clear of anything flammable, or towels soaked in hot water. Start at the faucet end and work back toward the coldest spot so meltwater can drain out as you go.
• Never use an open flame. The American Red Cross warns against thawing pipes with a blowtorch, kerosene or propane heater, or a charcoal stove — they can damage the pipe and are a serious fire risk. Keep heat on until full water pressure is restored.
• Check the rest of the house. If one pipe froze, others in unheated runs likely did too. And if you can’t reach the frozen area, can’t find it, or the pipe won’t thaw, call a licensed plumber rather than forcing it.

The pipes most likely to freeze are the ones exposed to the cold — outdoor hose bibs and sprinkler lines, and supply lines in unheated basements, crawl spaces, attics, garages, and cabinets against exterior walls. If a line does let go while you’re thawing it, go straight back to the burst-pipe steps above and shut the main.

How to prevent frozen pipes

Prevention is cheap next to a flooded floor. Both Ready.gov and the American Red Cross give the same core advice, and it works:

• Insulate the vulnerable pipes. Add insulation to attics, basements, and crawl spaces, and sleeve exposed hot- and cold-water pipes with foam pipe insulation or UL-listed heat tape or heat cable rated for the job.
• Let a faucet drip during a hard freeze. Running even a trickle of water through a pipe relieves the pressure that causes bursts and helps keep the line from freezing.
• Open cabinet doors. Under sinks on exterior walls, open the vanity and kitchen cabinet doors so heated room air can reach the plumbing.
• Keep the heat on and steady. Hold the thermostat at the same temperature day and night — a cold snap isn’t the time to set it back overnight — and if you leave town in winter, the Red Cross recommends leaving the heat set no lower than 55°F.
• Winterize outdoor plumbing. Before the first freeze, drain and store garden hoses, shut the inside valve that feeds each outdoor hose bib, and open the outside bib so any water left in the line can drain and expand without splitting the pipe.

If your pipes freeze most winters, the fix may be structural — insulating a crawl space or sealing the drafts that let cold air reach the plumbing. It’s also worth catching problems early: our guides on finding a hidden water leak and the signs of water damage help you spot a slow failure before it becomes a burst, and if lingering dampness follows a leak, see how to prevent mold.