Water Leak at Home? What to Do in the First 48 Hours to Prevent Mold

A burst pipe, overflowing washing machine or roof leak is stressful — but what you do in the first two days decides whether you’re dealing with a weekend of drying or months of mold remediation. Knowing what to do after a water leak is the difference — keep this plan handy.

Hours 0–1: Stop the water and stay safe

1. Shut off the water. Know where your main shut-off valve is (often in the basement, garage, utility room or near the water meter). For a single fixture, use its local valve.
2. Turn off electricity to affected areas at the breaker if water is near outlets, cords or appliances. Don’t walk through standing water to reach the panel — call an electrician or your utility.
3. Identify the water type:
   – Clean water (supply pipe, rain, tap overflow) — you can usually dry it yourself if caught quickly.
   – Grey water (washing machine, dishwasher) — clean carefully with protective gear.
   – Black water (sewage, toilet with waste, flood water) — call a professional. Don’t handle it without proper protection.
4. Move people and pets away from wet areas; watch for slip hazards and sagging ceilings.

Hours 1–3: Document for insurance

• Photograph and video everything before you move it: the source, water levels, damaged items, ceilings and floors.
• Keep damaged items (or photos and receipts) until your adjuster says you can discard them.
• Call your insurance company to report the claim and ask what they need. Many policies cover sudden, accidental leaks but not gradual ones.
• Write down the timeline — when you found the leak and what you did.

Hours 3–24: Remove water and wet materials

1. Remove standing water with a wet/dry vacuum, mops and towels.
2. Lift and move furniture. Put foil or wood blocks under furniture legs to prevent staining.
3. Pull up wet rugs and carpet. Carpet padding usually needs to be discarded; carpet may be saved if dried quickly and the water was clean.
4. Remove wet items — books, papers, cardboard, clothing — and dry or freeze important papers.
5. Open cabinets and drawers to let air circulate.
6. Check hidden areas: under sinks, inside walls (with a moisture meter), the ceiling below upstairs leaks.

Hours 24–48: Dry everything thoroughly

• Run fans pointed at wet surfaces and a dehumidifier continuously with doors and windows closed (or open windows only if outside air is dry).
• Use air conditioning to help remove moisture in warm weather.
• Cut away wet drywall about 12 inches above the water line if it’s soaked and won’t dry, and remove wet insulation. (Turn off power and check for wires and pipes first.)
• Measure moisture with a pin meter — keep drying until readings match dry areas of the house.
• Wear an N95 mask and gloves if you see any mold starting.

Shop dehumidifiers Shop moisture meters

After 48 hours: Watch for mold

Check affected areas for a musty smell, stains or spots over the next few weeks. Small patches on hard surfaces can be cleaned with detergent and water. Larger areas or mold on drywall need removal. See our mold hub guide, Hidden Mold in Walls and Mold Remediation Cost.

Fix the cause and prevent the next leak

• Repair the source properly — pipe, appliance hose, roof flashing or seal.
• Replace rubber washing machine hoses with braided stainless steel hoses every few years.
• Fit water leak sensors near the water heater, washing machine, dishwasher and under sinks. Smart sensors can alert your phone. See water leak detectors
• Insulate pipes in cold areas to prevent freezing.
• Know where your main shut-off valve is — and make sure it turns.

Health note: This article is for general information and isn’t medical advice. If you or someone in your home has symptoms such as wheezing, a persistent cough, a rash that spreads, or a fever after a bite, talk to a doctor or other qualified health professional. Read our disclaimer.