MoldHelpUSA
Mold under carpet is easy to miss because it grows where you cannot see it: in the pad, on the back of the carpet, and on the floor underneath. The carpet surface can look fine while the layers below stay wet for weeks. The EPA lists the underside of carpets and pads among the common hidden places for mold, and notes that the backing and pad must be dried along with the carpet or mold will likely result.
This guide covers the signs of mold under carpet, how to check safely, and when carpet can be dried out versus when it has to go.
Signs of mold under carpet
- A musty smell, especially one that gets stronger when you walk on the carpet or vacuum
- Carpet that feels damp, cool, or spongy
- Stains, discoloration, or dark spots, sometimes showing through from below
- Swollen, stained, or moldy baseboards and tack strips
- A recent leak, flood, pet accident, or spill that soaked through
- Carpet on a concrete slab or basement floor that tends to feel damp
- Allergy-like symptoms that seem worse in one room; these have many causes, so check the floor and talk to a doctor
How to check
- Pick a spot near the suspected area, ideally a corner or the edge of a closet where the carpet can be pulled back from the tack strip.
- Protect yourself. Wear gloves, goggles, and an N-95 respirator.
- Pull the carpet back gently and look at the back of the carpet, the pad, the tack strip, and the floor.
- Check moisture. A moisture meter, or simply feeling the pad and subfloor, tells you whether the area is still wet.
If you find heavy growth, stop there. Pulling up a large moldy area without containment can spread spores through the room. See signs of mold in your house.
Can the carpet be saved?
It depends on how long it was wet, what kind of water it was, and whether mold is already growing.
| Situation | Usual answer |
|---|---|
| Soaked by clean water, dried within 24 to 48 hours | Carpet can often be saved; the pad is usually replaced |
| Soaked by clean water and wet for several days | Often replaced, since it is slow to dry and likely to grow mold |
| Visible mold growth on the carpet or pad | Wall-to-wall carpet and pad are usually removed and discarded |
| Soaked by floodwater or sewage | Discard carpet and pad |
| Small washable area rug | Can often be machine washed and dried completely |
| Valuable rug | A professional rug cleaner with off-site drying facilities |
Why pad is almost always replaced: it absorbs water like a sponge and is nearly impossible to clean. The EPA's flood guidance notes that carpet soaked only with clean rainwater may be dried and saved, but that it takes a long time to dry and may be a source of microbial growth, so replacing it is worth considering. Carpet soaked with contaminated water should be discarded, because it cannot be fully disinfected.
What to do if you find mold under carpet
- Stop the water. Find the leak, appliance, or moisture source and fix it.
- Remove moldy carpet and pad. Cut it into strips, roll or fold it with the moldy side in, and bag or wrap it in plastic before carrying it through the house.
- Check the tack strip and baseboards. Moldy tack strip is replaced; check the bottom of the drywall behind the baseboard too.
- Clean the floor. Concrete can be scrubbed with detergent and water. Wood subfloor is cleaned and dried, and sections that are soft or rotted are replaced.
- Dry everything. Use fans and a dehumidifier, and check moisture before installing new flooring.
- Call a professional for large areas, flood or sewage water, mold on drywall or subfloor, or anyone in the home with asthma or a weakened immune system. See DIY vs. professional mold removal.
If the floor under the carpet is soft or stained, see mold on the subfloor.
Preventing mold under carpet
- Dry spills and leaks immediately, including the pad
- After carpet cleaning, run fans and air conditioning until it is completely dry
- Keep indoor humidity below 60 percent, as the EPA recommends
- Avoid carpet in bathrooms, laundry rooms, and on concrete floors that stay damp; the EPA advises against carpet in areas with ongoing moisture problems and on concrete in contact with the ground where condensation is frequent
What it costs
Removing mold from a small area typically runs about $500 to $1,500 for 10 to 100 square feet, according to HomeGuide's cost data, and replacing the carpet and pad is a separate cost. If the subfloor needs repair, that adds to the total. See our mold remediation cost guide.
Insurance
When the water came from a sudden, covered event, such as a burst pipe or a split washing machine hose, homeowners insurance often pays for water damage to carpet, and mold may be covered up to a separate mold limit. Mold from humidity or a slow leak is usually excluded. Flood damage falls under a flood policy, not homeowners insurance. See does homeowners insurance cover mold.
Carpet in Florida homes
Many Florida homes have tile on the main floor and carpet in bedrooms. After storms and flooding, carpet and pad soaked by floodwater should be removed. In homes left closed with the air conditioning off, carpet can pick up enough moisture from humid air to smell musty. See local pages for Fort Myers, Cape Coral, and the rest of Florida.
Outside Florida, see local pages for Houston, Plano, and Denver.
Next step
If you own your home and found mold under carpet, especially over a large area or after flooding, call the number on this page to be connected with an independent local mold remediation company.