Burst pipe: what to do in the first hour

1 Nov 20265 min readD1 Construction Group

If a pipe has burst, shut the water off at the main valve first. Then keep away from water that is near anything electrical, photograph the damage before you clean up, and start getting the water out.

Speed matters because of what happens next. The EPA’s guidance is to dry water-damaged areas and items within 24 to 48 hours; dried in that window, in most cases mold will not grow. This is the order to work in, written for a Minnesota winter, when a pipe frozen in an outside wall or an unheated space is the usual cause.

The first hour, step by step

1. Shut the water off at the main

The main shut-off is usually where the water line comes into the house, often in the basement near the water meter. A wheel handle closes clockwise; a lever closes with a quarter turn, so it sits across the pipe. If the leak is on a fixture with its own valve, like a supply line under a sink, that valve will do. If you are not sure, shut the main. If you can’t find it or it won’t turn, your city’s water department can usually shut the water off at the curb.

2. Make it safe before you wade in

Don’t walk into water that is near outlets, extension cords, appliances or the electrical panel. If you can reach the panel from somewhere dry, switch off the breakers that feed the wet area. If you can’t, stay out and leave it to an electrician or your utility. A ceiling that is sagging with water can come down, so keep people out from under it.

3. Photograph everything before you clean up

Take wide shots of each room, then close-ups of the damage, the broken pipe and anything ruined, before you move or throw anything out. Those photos are the record your insurance claim leans on.

4. Get the water out and the contents up

Mop, towel or wet-vac any standing water. Move rugs, electronics, papers and anything else that soaks up water out of the wet area, and set furniture legs on blocks or foil so they don’t stain the floor.

5. Make the calls

• A plumber, to repair the break before the water goes back on.
• Your insurer, to open a claim. Coverage depends on your policy, so ask early.
• A water damage restoration contractor, to measure where the water went and dry it properly.

Why the clock matters

Water doesn’t stay where it lands. It runs along joists, wicks up drywall and soaks into carpet pad and subfloor, and it keeps spreading until it is stopped and dried. That is why the stain you can see is rarely the whole story, and why we measure with moisture meters before anything is cut out.

1 2 3 4 5 6

1. The freeze. A supply pipe in an outside wall freezes in a cold snap and splits.
2. Inside the wall. Water runs down the wall cavity and soaks the insulation before anything shows.
3. Through the ceiling. It spreads across the ceiling of the room below and comes through as drips and stains.
4. On the floor. It pools on the flooring and works into the subfloor underneath.
5. The main shut-off. Usually where the water line comes in, near the meter. Closing it is step one.
6. The electrical panel. Stay clear if there is water near it; switch breakers off only from somewhere dry.

What usually happens to each material:

• Drywall is dried in place if it isn’t swollen and the seams are intact. Otherwise it is cut out and replaced.
• Insulation, fiberglass or cellulose, is removed and replaced.
• Carpet and pad have the water extracted and are dried fast, or removed. The subfloor underneath has to be dried as well.

What not to do

• Don’t thaw a frozen pipe with an open flame. The Red Cross rules out a blowtorch, a kerosene or propane heater, a charcoal stove or any other open-flame device.
• Don’t turn the water back on until the pipe has been repaired.
• Don’t close up walls or lay new flooring until the moisture readings say the structure is dry. Paint over a stain and the wet framing behind it stays wet.
• Don’t treat dirty water like clean water. If it came from a sewer backup or is otherwise contaminated, the EPA’s advice is to call in a professional.

If a pipe is frozen but hasn’t burst

A faucet that gives a trickle or nothing on a cold morning usually means a frozen pipe. The Red Cross’s advice:

• Keep the faucet open.
• Warm the frozen section with an electric heating pad wrapped around the pipe, an electric hair dryer, a portable space heater kept away from anything flammable, or towels soaked in hot water.
• Keep the heat on it until full water pressure is back.
• Call a licensed plumber if you can’t find the frozen section, can’t reach it, or can’t thaw it.

Before the next cold snap

• Keep the thermostat at the same temperature day and night.
• If you are going away in cold weather, leave the heat on, set no lower than 55°F.
• When it is very cold, let cold water drip from faucets served by exposed pipes.
• Open kitchen and bathroom cabinet doors so warmer air can reach the plumbing.
• Close the inside valves that feed outdoor hose bibs.
• Find your main shut-off now, while nothing is leaking, and make sure it turns.

The first five come from the Red Cross’s guidance on frozen pipes. The last one is ours: the worst time to look for the valve is with water coming through the ceiling.

Common questions

Does homeowners insurance cover a burst pipe?

Often, when the damage is sudden and accidental. Damage from a slow leak that went on for months is usually treated differently. Your policy decides, so call your insurer early, and keep the photos you took before cleanup.

Can I dry it out myself with fans?

A small spill of clean water caught straight away, maybe. Once water has run under flooring, into wall cavities or through a ceiling, it needs measuring, because a surface can feel dry while the framing behind it is still wet.

How long does drying take?

It depends on what got wet and how far the water went. A room is dry when the moisture readings say so, not after a set number of days, which is why we meter before we rebuild.

Sources

• U.S. EPA, A Brief Guide to Mold, Moisture and Your Home
• American Red Cross, Preventing and Thawing Frozen Pipes
• Nationwide, What to Do When a Pipe Bursts