A burst pipe is one of the most urgent plumbing emergencies a homeowner can face. Water pressure means even a small crack can discharge hundreds of gallons into walls, ceilings, and floors in a short amount of time. Here's exactly what to do — in order — when it happens.
Step 1: Turn Off the Main Water Supply (Immediately)
Find your main shut-off valve and turn it off. In most homes, this is located:
- Where the main supply line enters the house (basement, crawlspace, or utility room)
- Near the water meter (sometimes outside, in a meter box)
- In the garage or near the water heater
Every adult in your household should know where this valve is before an emergency happens. The valve is usually a gate valve (turn clockwise to close) or a ball valve (turn the lever 90° until perpendicular to the pipe).
Step 2: Turn Off the Water Heater
Once the main supply is off, turn off your water heater to prevent damage. For gas heaters, turn the thermostat to "pilot." For electric heaters, switch off the circuit breaker. Running a water heater without water flowing through it can damage the heating element.
Step 3: Open Cold Taps to Drain the System
Open cold water taps at the highest and lowest points in the house. This drains remaining water from the pipes and reduces pressure at the burst location, slowing the flow of water into your home.
Step 4: Contain and Document the Damage
Use buckets, towels, and mops to contain water that's already in your home. Move furniture, electronics, and valuables out of the affected area immediately. Take photos and video of all water damage before you clean anything — your insurance company will require documentation.
Step 5: Call a Plumber
Call a licensed emergency plumber. Most plumbing companies offer 24/7 emergency service. Be specific about what you're seeing: the location (which room, inside wall vs. exposed), whether water is still flowing, and how much water has accumulated. This helps them come prepared with the right parts and equipment.
Step 6: Start Drying Immediately
If water sat in walls or under flooring for more than 24–48 hours, mold can begin to grow. Open windows, run dehumidifiers and fans, and if the water penetrated drywall or insulation, it likely needs to be removed. Many areas have water damage restoration companies that can deploy commercial drying equipment within hours.
Why Pipes Burst
The most common causes:
- Freezing — water expands when frozen, creating enough pressure to split pipes
- Corrosion — older galvanized steel pipes corrode from inside out
- High water pressure — pressure above 80 PSI stresses pipe joints
- Physical damage — accidental puncture during renovations
- Tree root intrusion — roots infiltrate and crack underground supply lines