Burst Pipe
A burst pipe is a pipe that has ruptured, creating an uncontrolled release of water. Burst pipes are plumbing emergencies that can discharge hundreds of gallons per hour — a ¾-inch supply line at 60 PSI can release over 10 gallons per minute. Knowing how to respond in the first minutes dramatically limits the damage.
What causes pipes to burst
- Freezing: the most common cause in cold climates. Water expands 9% when it freezes — in a rigid pipe, this pressure (up to 2,000 PSI) cracks or splits the pipe, which often doesn't appear until the ice thaws and water rushes out.
- Corrosion: galvanized steel pipes in older homes develop pinholes that grow into splits over time. Aggressive water chemistry (low pH, high chlorine) accelerates copper pitting.
- Water hammer: repeated hydraulic shock from fast-closing valves (solenoid valves, quick-closing fixtures) weakens pipe joints and fittings over time.
- High pressure: sustained pressure above 80 PSI stresses joints and fittings — a failed pressure reducing valve (PRV) can allow street pressure (80–150 PSI) to reach household pipes rated for 80 PSI maximum.
- Physical damage: construction, nail guns, and drilling accidents puncture pipes concealed in walls.
- Age and material: polybutylene pipes (installed 1978–1995) are notorious for splitting due to chlorine degradation — an estimated 10 million U.S. homes still have polybutylene supply systems.
Immediate response
- Close the main shutoff valve immediately — every second counts.
- Turn off electricity to any affected areas if water is near outlets, panels, or appliances.
- Open all faucets to drain remaining water from the system and relieve pressure.
- Document damage with photos before cleanup.
- Call a plumber and, if damage is significant, your homeowner's insurance.
Repair
A burst supply pipe requires cutting out the damaged section and replacing it — either with the same material (copper-to-copper, PEX-to-PEX) or a compatible material with appropriate transition fittings. Push-fit slip couplings (SharkBite) make emergency repairs fast without a torch. A plumber charges $200–$800 for a straightforward burst pipe repair; extensive damage requiring wall access and drywall repair runs $1,000–$5,000+.