A pipe burst. What do I do in the next five minutes?

A supply line does not leak politely when it lets go. It sprays. A half-inch line at street pressure can put out gallons a minute, and in a slab home with no basement to catch it, that water goes across the tile, under the baseboards, and into every room on the same level. The next five minutes decide how much of the house gets wet.

Minute one: shut off the water

Every house has a main shutoff valve. In most homes here it is a lever or a round handle on the pipe where the water enters, usually on an outside wall near a hose bib, in the garage, or in a box at the front of the house. Turn a lever a quarter turn so it sits across the pipe. Turn a round handle clockwise until it stops.

If you cannot find it or it will not turn, go to the meter at the street. Pull the lid and turn the valve on the house side of the meter with a wrench or a meter key. Utilities ask that you leave their side of the meter alone, but the house side is yours to close.

If you know where the burst is and the line has its own stop, a supply valve under a sink or behind a toilet, close that first; it stops the water without draining the whole house. Then decide whether you still need the main.

Seasonal residents: if you are not in the house, call whoever is. This is the reason a neighbor or a manager should know where the valve is before you leave.

Minute two: drain the pressure

With the main closed, open a faucet on the lowest level and an outdoor hose bib. The water in the pipes drains out through the open faucets instead of the burst, and the spray at the break stops within a minute or two. Leave the faucets open until the plumber arrives.

Minute three: get the water away from the electricity

Water and electricity share a house, and a burst puts them together. If water is pooling near outlets, appliances, a power strip, or the electrical panel, do not walk through it to reach a switch. If the panel is in a dry spot, switch off the breakers for the wet rooms. If the panel itself is wet or you would have to stand in water to reach it, leave it, get out of the wet area, and call the utility to cut power at the meter. Do not unplug anything that is standing in water.

Minute four: protect what you can

• Move belongings off the floor: rugs, boxes, furniture legs onto foil or blocks, anything in a closet on the wet side.
• Photograph everything before you touch it. Wide shots of each room, close shots of the burst, the meter reading, the water line on the walls. Insurers ask for this, and you cannot go back and take it later.
• Pull up wet rugs and towels and get them outside. Wet fabric on tile holds water against the grout and the baseboards.
• Start air moving. Open the wet rooms to the air conditioning, run every fan you own, and if you have a dehumidifier, put it in the wettest room. In our humidity, drywall that stays damp for two days is on its way to mold.

Minute five: turn off the water heater

If the house has drained, the water heater may be sitting with air in the top of the tank. An electric heater that fires its elements dry burns them out; a gas heater can crack. Switch the breaker off, or turn the gas control to pilot or off, and leave it off until the line is repaired, the main is back on, and hot water runs at a faucet.

Why pipes burst here

Freeze bursts get all the attention nationally and almost never happen in Lee and Collier County. Our bursts come from the pipe and its fittings giving up:

• Supply lines and fittings. The flexible line to a toilet, faucet, washing machine, or icemaker is the most common failure. A rubber washer hose or a low-grade braided line lets go at the crimp, and it does so at full house pressure whether you are home or not.
• Polybutylene. The gray plastic pipe used in many homes from the late 1970s to the mid 1990s fails at its fittings and along its length as chlorine breaks it down from the inside.
• Aged CPVC. The cream-colored plastic from the 1980s and 90s gets brittle in a hot attic and cracks when it is bumped or when a fitting is stressed.
• Corroded copper. A pinhole is a slow leak until the wall of the pipe thins enough to open up.
• Water hammer. A washer or dishwasher valve slamming shut sends a shock down the line. Over years it works joints loose and splits weak spots.
• Pressure. A failed pressure regulator or a night of very high utility pressure can push an old system past what it will take.

What the plumber does on arrival

The first job is to confirm the water is off and find the break, which sometimes means opening drywall or a section of ceiling. The failed section is cut out and replaced, or the line is capped so the rest of the house can have water back while a larger repair is planned. Then the system is pressurized and checked, the water heater is refilled and turned back on, and every faucet is run to clear air. Before leaving, the plumber should tell you what failed and whether it is a one-off or a sign of the rest of the pipe.

If the burst was polybutylene, old CPVC, or the second copper leak in a year, that conversation becomes a repipe conversation. The first burst is the warning.

This is not a wait-and-see problem, and it is not a DIY repair beyond closing the valve and the steps above. Cutting into a wet wall, splicing pipe, or turning the water heater back on without knowing the tank is full are the places people get hurt or make it worse. If a pipe has burst in your house, shut the water, work the list, and call. A plumber answers 24 hours a day.