Burst Pipe Emergency: What to Do Right Now

Common Symptoms

• Water spraying or shooting from a visible pipe
• Sudden flooding in a room, basement, or crawl space
• Dramatic loss of water pressure throughout the house
• Wet ceiling, walls, or floors with no obvious source
• Loud banging or water-hammer sound in the walls followed by reduced flow
• Water meter spinning rapidly with all faucets off

Most Likely Causes

1. 1

   Frozen Pipe That Split (Most Common in Cold Climates)

   When water freezes inside a pipe, it expands approximately 9% in volume — enough force to rupture copper, galvanized steel, or PVC pipe from the inside. A pipe that freezes slowly often survives intact, but rapid temperature swings or a sustained deep freeze causes the pipe wall to fail. The burst typically occurs as the pipe begins to thaw, when the ice plug melts and full supply pressure hits the weakened cracked section. See the [Frozen Pipe Thawing](/fixes/frozen-pipe-thawing) guide for prevention.

2. 2

   Corrosion or Physical Damage

   Older pipes — especially galvanized steel pipes in homes built before 1960 — corrode from the inside over decades. Corrosion thins the pipe wall until it can no longer hold supply pressure. Copper pipes can also be compromised by pinhole corrosion caused by acidic water chemistry. Physical damage from impact (driving a nail through a wall into a pipe, or shifting foundation movement) can also cause an immediate burst or a slow developing crack.

3. 3

   Water Hammer and Pressure Surge

   Water hammer — the banging sound when a valve closes suddenly — creates a hydraulic shock wave in the supply line. Repeated water hammer over time fatigues pipe fittings and solder joints, eventually causing a joint failure or pipe crack. Very high supply pressure (above 80 psi) also stresses pipe walls and fittings continuously. If your home's pressure-reducing valve (PRV) has failed, supply pressure may have risen to levels that can burst pipe joints.

4. 4

   Age and Failure of a Weakened Joint or Fitting

   Solder joints on copper pipes, compression fittings, and threaded galvanized connections can develop slow weeps over time that accelerate to a full burst without warning. A fitting that showed occasional dripping but was not repaired will eventually fail completely. Any pipe joint under continuous pressure is a potential failure point — regular inspection of visible supply lines (under sinks, in mechanical rooms, in crawl spaces) catches weeping joints before they become emergencies.

Quick DIY Checks

1. 1Step 1 — shut off the main water supply immediately: this is the single most important action. Every second of delay allows more water damage. The main water shutoff valve is typically located: (a) near the water meter at the front of the house — check the basement wall closest to the street, the utility room, or a covered box at the base of the exterior wall; (b) in a crawl space near where the main supply line enters the foundation; or (c) in a utility closet. Turn the valve fully clockwise (gate valve) or rotate the handle 90° perpendicular to the pipe (ball valve) to close. If you cannot locate the main shutoff, call your water utility — the meter curb stop at the street can be closed with a meter key. Do this BEFORE anything else.
2. 2Step 2 — cut electricity to affected areas if water is near electrical panels: if the flooding water has reached near any electrical panel, outlet, appliance, or light fixture, do NOT enter the water — go to your electrical panel (breaker box) and switch off the breakers for the affected area. If the panel itself is in the flooded area or near water, call your utility company to cut power at the meter — do not enter a flooded area with live electrical components. Water and electricity together are immediately life-threatening. Only re-enter the area once power is confirmed off and a qualified electrician has cleared it.
3. 3Step 3 — relieve pressure and drain remaining water: with the main water supply off, open all faucets in the house to drain the supply lines — this reduces the amount of water remaining in the pipes and prevents residual pressure from continuing to push water through the burst. Flush all toilets once. Open the lowest faucet in the house first (a basement utility sink or outdoor hose bib) to drain the system quickly by gravity. This step also confirms the main shutoff is fully closed — if water continues to flow after 2–3 minutes with the main off, the shutoff valve has not fully closed and you need the street-level curb stop closed instead.

Repair vs Replace

Recommended Tools & Parts

• Rescue Tape Self-Fusing Silicone Repair Tape

  Self-fusing silicone tape that creates a waterproof seal around a burst or cracked pipe without adhesive. Stretches to 300% and fuses to itself (not to the pipe) to form a solid sleeve rated to 950 PSI. Emergency temporary repair for pinhole leaks and small splits. Extend 2 inches past the damage on each side.

  $8–$14

  Buy on Amazon →

• Fernco Flexible Pipe Repair Clamp 1-inch

  Rubber-and-stainless-steel pipe repair clamp for a stronger temporary seal on split or cracked pipes. Wraps around the pipe and is tightened with included clamp screws — creates a mechanical seal rated for residential supply pressure. Available in 1/2-inch through 2-inch pipe sizes.

  $12–$22

  Buy on Amazon →

• SharkBite 1/2 in. Push-to-Connect Coupling

  Push-fit copper/PVC/PEX coupling for permanent pipe repair without soldering. Cut out the damaged section, insert the coupling on each pipe end — no tools required. Rated to 200 PSI at 200°F. For a permanent DIY repair after emergency stabilization. Works on copper, CPVC, and PEX supply lines.

  $8–$15 each

  Buy on Amazon →

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