After a frozen pipe bursts, shut off the main water valve, cut power to wet areas if it is safe, and call a plumber. Photograph the damage, remove standing water and soaked items, and start drying right away. The EPA says materials dried within 24 to 48 hours usually will not grow mold. Then have hidden moisture checked.
The first real cold snap of a Michigan winter is when a lot of plumbing gets tested. A pipe that has been fine since spring can freeze overnight in an unheated garage, a crawl space under an addition or an outside wall, and you may not know until you hear water running where it should not be.
In Ann Arbor, that can happen in an older home on the Old West Side with plumbing tucked into exterior walls just as easily as in a newer house with a finished basement. This post walks through what to do in the first two days, how to tell when drying is not enough, and how to keep pipes from freezing in the first place.
Your first steps after a pipe bursts
The clock starts the moment water gets loose. Here is what to do, in order.
- Shut off the main water valve. Know where it is before winter. It is usually in the basement or utility area where the water line enters the house.
- Turn off power to wet areas if you can do it safely. If water is near outlets, cords or the electrical panel, do not walk through it. Call your utility or an electrician.
- Call a licensed plumber. The pipe needs a proper repair before the water goes back on.
- Take photos and video. Record the pipe, the water and every damaged item before you move much. The Michigan Department of Insurance and Financial Services says to notify your agent or insurance company right away and to photograph or record the damage.
- Remove standing water. Mop, use a wet vacuum, and push water toward a floor drain. The less water left sitting, the faster everything dries.
- Get wet items out. Move rugs, boxes, cushions and stored items to a dry area. Cardboard and paper soak up water fast.
- Start drying. Run fans and a dehumidifier, open interior doors and keep the heat on. Make only temporary repairs to stop further damage, and keep receipts, as the state's homeowners guide advises.
Why does the 24 to 48 hour window matter so much?
Mold needs moisture to grow, and building materials that stay wet give it what it needs. The EPA puts it plainly: dry water-damaged areas and items within 24 to 48 hours to prevent mold growth. When wet materials are dried within that window, in most cases mold will not grow.
That is why speed matters more than anything else in the first two days. A floor that is dry by tomorrow afternoon is a very different situation from a wall cavity that is still damp next week.
What can be dried, and what has to go?
Not everything that gets wet needs to be thrown out. The EPA's water damage cleanup guidance sorts materials by how well they dry.
- Drywall. It may be dried in place if there is no obvious swelling and the seams are intact. If it is swollen or the seams have opened, it should be removed and replaced.
- Insulation. Wet fiberglass and cellulose insulation should be discarded and replaced. This is common when a pipe bursts inside a wall or ceiling.
- Carpet and pad. These need to be dried within 24 to 48 hours, using water extraction, a dehumidifier and fans.
- Wood. Remove moisture right away and dry it with dehumidifiers, gentle heat and fans.
- Hard surfaces. Plastic, metal and similar non-porous surfaces can be wiped down and dried.
The EPA also notes that porous materials that become moldy may have to be thrown away. If something was wet for days before anyone found it, assume it will be harder to save.
Where does water hide after a burst pipe?
The water you can see is rarely all of it. Water follows gravity and wicks into materials, so it often travels farther than it looks.
- Inside wall cavities below the break, soaking insulation and the bottom plate
- Under flooring, including the subfloor beneath vinyl, laminate or carpet
- Behind baseboards and cabinets, especially in kitchens and bathrooms
- In the ceiling below, if the break was on an upper floor
- In the basement or crawl space under the room where it happened
This is why a moisture check matters even when the floor looks dry. We start with a free visual mold inspection using a thermal imaging camera and a moisture meter, which can show damp areas behind surfaces without opening walls just to look.
How do you know if mold has already started?
If the leak was caught fast and everything dried within a day or two, you may never see a problem. Watch for these signs over the next few weeks:
- A musty smell that was not there before
- Staining or discoloration on drywall, baseboard or ceiling
- Paint that bubbles or peels in the area that got wet
- Flooring that feels soft, cups or lifts
- Spots of growth on the back of stored items or on cabinet bases
If you notice any of these, the moisture may have gone deeper than it seemed.
Which pipes are most likely to freeze in an Ann Arbor home?
The American Red Cross lists three groups of pipes that are most likely to freeze:
- Pipes exposed to severe cold, like outdoor hose bibs, swimming pool supply lines and sprinkler lines
- Water supply pipes in unheated areas like basements, crawl spaces, attics, garages or kitchen cabinets
- Pipes that run against exterior walls with little or no insulation
In Ann Arbor, that covers a lot of houses. Older homes often have plumbing in outside walls and basements that were never meant to be heated living space. Newer homes have garages with supply lines and finished basements where a frozen pipe can do damage behind drywall. A kitchen sink on an outside wall is one of the most common trouble spots.
How can you keep pipes from freezing this winter?
The Red Cross recommends a few simple steps, most of which cost nothing.
- Remove, drain and store garden hoses, and close the inside valves that feed outdoor hose bibs.
- Drain pool and sprinkler supply lines following the manufacturer's or installer's directions.
- Keep garage doors closed if there are water lines in the garage.
- Open kitchen and bathroom cabinet doors so warmer air reaches the plumbing.
- When it is very cold, let cold water drip from faucets served by exposed pipes.
- Keep the thermostat at the same temperature day and night.
- If you will be away, set the heat no lower than 55 degrees.
What if a pipe is frozen but has not burst?
The Red Cross says that if you turn on a faucet and only a trickle comes out, suspect a frozen pipe. Keep that faucet open, since running water helps melt the ice. Apply gentle heat until full water pressure comes back, and never use a blowtorch, kerosene or propane heater, charcoal stove or other open flame. Check your other faucets too, because if one pipe freezes, others may as well. If you cannot thaw it, call a licensed plumber.
What about insurance?
Coverage depends on your policy and how the damage happened, so read your own policy and talk with your agent. The Michigan Department of Insurance and Financial Services advises notifying your insurer right away, documenting the damage, making only temporary repairs and keeping receipts, and waiting on permanent repairs until the insurer has inspected.
Had a pipe burst this winter?
Once the plumber has fixed the pipe and the water is cleaned up, the question is whether anything is still wet behind the walls or under the floor. Book a free visual mold inspection with Mold Medics Ann Arbor, and we will check for hidden moisture with a thermal imaging camera and a moisture meter.
