What to Do When a Pipe Bursts

Why it matters

At ordinary house pressure, a split half-inch line empties a lot of water very quickly. Water runs along joists, soaks insulation, wicks up drywall and finds its way to the basement floor. Every minute the valve stays open adds to the cleanup, the drying time and the insurance claim. Most of what limits damage is something a homeowner can do before any plumber arrives.

Step by step

1. Close the main valve. Look downstairs on the street-side wall by the meter. Spin a round handle clockwise to its stop, or swing a lever ninety degrees across the pipe. Our letter on finding your main shut-off valve covers this in detail.
2. Deal with electricity. If water is near outlets, a panel or appliances, trip those breakers, but only from a dry spot.
3. Drain the lines. Open the lowest tap in the house, often a laundry tub or basement sink, and an upper tap to let air in. This empties the pipes so less water escapes from the break.
4. Protect the water heater. If the water will be off for long, turn a gas heater's dial to its pilot or vacation mark and switch off an electric heater's breaker.
5. Move belongings and start cleanup. Lift rugs, boxes and electronics. Mop and towel standing water and run fans if it is safe.
6. Document. Photograph the break, the wet areas and damaged items before tidying up.
7. Call a plumber and your insurer. Tell the plumber the pipe material if you know it and whether the water is now stopped.

Common mistakes

• Trying to stop the leak with a hand or a rag before closing the valve.
• Walking into a flooded basement with power still on.
• Using a torch or open flame to thaw a frozen section next to the break.
• Turning the water back on too soon to check, which can reopen a crack you could not see.
• Leaving wet drywall and insulation in place for days, which invites mould.

When to call a plumber

Any pipe that has actually split needs a proper repair: the damaged section cut out and replaced with sound pipe and approved fittings. Clamps and tape are temporary at best. Call right away if you cannot close the main valve, if water is near the electrical panel, or if more than one pipe has failed. With the water stopped and the mess contained, phone us without panic. Our emergency plumbing service handles exactly these calls. Once the repair is done, ask why the pipe failed. Frost, age and material all point to different prevention steps for next winter.