Mold after flooding in Nashville

Why do Nashville floods turn into mold jobs?

Middle Tennessee floods tend to come fast. Heavy spring storms push the Cumberland River and its creeks out of their banks, and water reaches homes that have never flooded before. In the May 2010 flood, Nashville recorded 13.57 inches of rain over May 1 and 2, and the Cumberland at Nashville crested at 52.55 feet on May 3, far above its 40-foot flood stage. Mill Creek's gauge in Antioch set a record crest of 26.10 feet, and the Harpeth River at Kingston Springs set a record that washed the gauge away.

The March 27-28, 2021 storm was different but just as damaging: 7 to 9 inches of rain over the southern and eastern metro, 7.01 inches at the airport, and rapid rises that flooded hundreds of homes and businesses. Seven Mile Creek at Blackman Road hit its highest level on record, and Hermitage measured 7.16 inches.

What both events share is time. Water soaks into crawl spaces, subfloors, drywall and insulation, and many homes stay wet for days because power is out, roads are closed or contractors are booked. Mold needs only moisture and something to feed on, and a flooded house offers plenty of both.

What should you do in the first 48 hours?

EPA and the Tennessee Department of Health both put the window at roughly 24 to 48 hours. Mold can begin growing within 48 hours of flooding, so the order of work matters.

1. Make sure the house is safe to enter. Stay out until power is off to wet areas and the structure is sound.
2. Keep vulnerable people out. EPA advises that people with asthma or weakened immune systems stay away from moldy sites and that children not take part in disaster cleanup. Anyone working inside should wear at least an N-95 respirator.
3. Document everything. Photograph water lines on walls, soaked flooring, damaged contents and the outside of the house before anything is hauled to the curb.
4. Get standing water out and air moving. Open the house when the weather allows, and use fans and dehumidifiers once power is safe.
5. Do not run a flooded HVAC system. EPA warns that running a system you know or suspect is contaminated can spread mold through the building. Ductwork in a flooded crawl space should be checked before the system comes back on.
6. Pull wet porous items. The Department of Health advises discarding wet items that cannot be cleaned or dried within 48 hours.

What has to be torn out, and what can be cleaned?

The general rule from EPA: hard, nonporous surfaces can usually be cleaned and dried, while porous materials that stayed wet often cannot. Painting or caulking over mold does not solve anything.

Hidden spaces are where flood mold usually survives a quick cleanup. Wall cavities, the underside of subfloors and duct runs under the house stay damp long after the rooms look dry. If you are unsure, see our page on mold inside wall cavities and the one on crawl space mold under Nashville homes.

What about furniture and belongings?

Contents follow the same logic as building materials. Upholstered furniture, mattresses, pillows, stuffed toys and paper goods that soaked up floodwater are hard to dry all the way through, and the Department of Health advises discarding wet items that cannot be cleaned or dried within 48 hours. Solid wood, metal and plastic pieces can usually be cleaned and dried. Before anything goes to the curb, photograph it and list it, since adjusters often ask for an inventory. Set aside photos and documents you want to save and dry them first; everything else can wait a day.

When is flood mold a job for a professional?

EPA says a homeowner can usually handle a moldy area under about 10 square feet, roughly a 3 foot by 3 foot patch. Flooding rarely stays that small. When there is a lot of water damage or more than 10 square feet of growth, EPA points to its commercial remediation guidance, which calls for containment, protective equipment and careful removal. That is the work a Nashville mold remediation company does.

Call for help when:

• Water reached drywall, insulation or the subfloor and sat for more than two days
• The crawl space or basement held standing water
• Ductwork or the air handler was under water (see HVAC and duct mold)
• Anyone in the home has asthma or a weakened immune system
• You smell a musty odor after the house has supposedly dried

Does flood insurance cover mold?

Read your policy closely. The National Flood Insurance Program's standard policy pays for direct physical loss from flood, but it excludes mold, mildew and moisture damage that results from conditions within the policyholder's control. FEMA lists failure to inspect and maintain the property after floodwater recedes as one of those conditions. In one published appeal, FEMA declined to pay for mold found months after a flood.

The practical lesson: start drying right away, keep receipts for fans, dehumidifiers and tear-out, and photograph each step. Standard homeowners policies treat flooding separately from other water losses, so check both. Our guide on whether homeowners insurance covers mold in Tennessee covers the non-flood side.

What does flood mold cleanup cost?

Angi's 2026 national data puts typical mold remediation at $1,223 to $3,758, with a national average of $2,369 and most pros charging $10 to $25 per square foot. Flood jobs often run higher because they spread across rooms: Angi's national range for mold in walls is $1,000 to $20,000, crawl spaces run $500 to $2,000, and whole-house remediation runs $10,000 to $30,000. These are national figures; Middle Tennessee prices vary with access, square footage and how much material comes out. Our Nashville mold cost guide breaks down what drives a quote.

What rules apply to the contractor you hire?

After a big flood, out-of-town crews show up quickly. Tennessee requires a contractor's license before anyone bids on a project of $25,000 or more, labor and materials included, and the job cannot be split into phases to slip under that limit. For mold work, look for a contractor holding the Tennessee license with the mold remediation (S-F) classification. Residential jobs from $3,000 to under $25,000 in Davidson, Robertson and Rutherford counties need the state Home Improvement license. You can check either on TDCI's Verify a License search. Our guide to checking a Tennessee mold company before you hire walks through it.

Rebuilding is a separate step. Metro Codes requires a permit for repairs beyond normal maintenance, such as replacing supporting walls or altering load-bearing members, while painting and floor finishing do not need one.

How do you know the cleanup worked?

EPA says sampling is usually unnecessary when mold is visible, but surface sampling can help show whether an area has been adequately cleaned. Many owners hire an independent inspector for that final check rather than relying on the company that did the removal, a practice Angi recommends. See post-remediation clearance testing for how that works.

How can you check your flood risk before the next storm?

Metro Water Services shows regulated floodplains on FEMA Flood Insurance Rate Maps, which you can view online or through Metro's Parcel Viewer. Its Development Services Division can provide your FIRM zone, base flood elevation and elevation certificates on request. Metro also notes that homes outside the mapped flood hazard area are not guaranteed to stay dry, which the 2021 creek flooding showed. Homeowners in Franklin and other Harpeth River towns should check with their own city's floodplain office as well.