Mold after a flood or leak: the first two days matter

Both EPA and the Oklahoma DEQ give the same deadline: wet building materials and belongings that are dried within 24 to 48 hours usually won't grow mold. Past that window, drywall, carpet pad and insulation that stayed wet are likely to need removal. Whether the water came from a hailstorm, a backed-up storm drain, an overflowing AC pan or a split supply line under the sink, the first two days decide how big the bill gets.

The first day

1. Stop the water at the main shutoff or the fixture, and turn off power to wet areas if it's safe to reach the panel.
2. Photograph everything before you move it: water lines on walls, wet flooring, damaged contents. Your insurer will want it.
3. Call your insurance agent and ask what's covered and whether they want their adjuster to see it before tear-out.
4. Get air moving. Fans and dehumidifiers, windows open only if the outside air is drier than inside (in a Tulsa summer it often isn't).
5. Pull up wet rugs and pad and move furniture off wet carpet.

Sewage and floodwater are a different job

If the water came from a sewer backup, a creek or river, or ran across the yard before coming in, treat it as contaminated. EPA's advice is to bring in a professional experienced with buildings damaged by contaminated water rather than cleaning it yourself. Porous materials it soaked usually can't be saved.

Don't run a contaminated system

If water got into the furnace, air handler or ductwork, EPA says not to run the HVAC system if you suspect it's contaminated with mold, because it can spread spores through the house. Oklahoma's real estate disclosure form even asks sellers specifically about water in the heating and air conditioning ducts, which tells you how often it happens.

Tulsa knows floods

This is a city that rebuilt its whole approach to flooding after hard lessons:

• Memorial Day 1984: 6 to 15 inches of rain in about eight hours flooded more than 5,500 buildings, killed 14 people and caused about $180 million in damage, most of it along Mingo Creek (NWS Tulsa). The city later relocated about 300 flooded homes and created its stormwater department.
• October 1986: after weeks of rain, the Arkansas River at Tulsa crested at 25.21 feet, the highest on record there, flooding parts of Sand Springs, Tulsa, Jenks and Bixby (NWS Tulsa).
• May 2019: the Corps of Engineers released about 275,000 cubic feet per second from Keystone Dam, the most since 1986, loading the roughly 20-mile levee system between Sand Springs and Tulsa (U.S. Army Corps of Engineers).

Most homes in the area will never see river water inside, but a flash flood, a clogged storm inlet or a downpour on saturated ground can still put an inch on the floor.

Flood insurance in Tulsa

Most homeowners and renters policies don't cover flood damage, and a new NFIP flood policy typically takes 30 days to start. Tulsa holds the top Class 1 rating in FEMA's Community Rating System, one of only two communities nationwide, which made NFIP policies inside city limits eligible for a 45 percent discount starting in 2022. Ask your agent what applies to your address.

When to call for remediation

If materials stayed wet more than two days, the wet area is bigger than about 10 square feet, or you already smell mustiness, it's time for a professional mold remediation company. For a sense of price before anyone arrives, see what mold removal costs.

Good questions

How fast does mold grow after water damage?

EPA and the Oklahoma DEQ both say materials dried within 24 to 48 hours usually won't grow mold. After that, growth on wet porous materials becomes likely.

Does homeowners insurance cover mold after a leak?

It depends on your policy and what caused the water. Ask your agent before tear-out starts, and photograph everything first. Flood damage is a separate question, since most homeowners and renters policies don't cover flooding.

Can I use bleach on flood-damaged walls?

Bleach doesn't fix wet drywall or insulation that has to come out anyway. EPA's home guidance is to scrub hard surfaces with detergent and water and dry them; soaked porous materials usually get removed.