That damp, earthy, “old basement” smell is one of the most common complaints we hear from South Florida homeowners. Sometimes it’s a simple humidity problem. Sometimes it’s a sign of hidden water. Either way, the smell won’t go away for good until you find out what’s causing it.
Common Causes of a Musty Smell in Florida Homes
- High indoor humidity. If the AC isn’t pulling enough moisture out of the air, fabrics, carpets and closets start to smell.
- AC problems. A clogged drain line, a wet drain pan, or a damp AC closet can create a musty smell that blows through the whole house.
- Hidden leaks. Slow leaks under sinks, behind toilets, behind dishwashers, or from a unit upstairs.
- A home that was closed up. Seasonal homes and rentals with the AC off or set high can turn musty fast.
- Mold. Mold growing behind walls, under flooring, or in the AC system often smells musty before you ever see it.
How to Find the Source
- Follow your nose. Is the smell strongest in one room, a closet, or near the AC?
- Check your humidity. A simple humidity meter helps. Most homes do best between 30% and 50%. In Florida, run the AC to keep it down.
- Look in the AC closet. Check the drain pan, the floor, and the walls around the unit.
- Check under sinks and around toilets for stains, soft spots, or warped cabinet bottoms.
- Look at baseboards and the bottoms of walls for swelling, stains, or peeling paint.
Our guides on finding hidden mold and mold in your AC closet walk through this in more detail.
If It’s Moisture or Mold: Fix That First
If you find water damage or mold, no spray or treatment will fix the smell until the source is handled. The leak has to be stopped, wet materials dried or removed, and any mold properly remediated. A mold inspection with moisture meters and an infrared (thermal) camera can find moisture hiding inside walls, and licensed mold remediation takes care of the rest.
If the Source Is Fixed but the Smell Stays
This happens a lot. The leak is repaired, the mold is gone, the house is dry, and it still smells musty. The odor has soaked into fabrics, cabinets, and the AC system. (See musty smell after mold removal.)
That’s where our whole-home odor removal treatment comes in. It treats the air throughout the entire home, including one AC system, to remove lingering odors. You’ll be out of the home for about 8 hours. One important note: this is an odor treatment. It doesn’t fix leaks or replace mold remediation, which is why we always handle the source first.
Who Do You Call for a Musty Smell in Your House?
- The smell only shows up when the AC runs: start with an AC technician to check the drain line, drain pan and coil. If there’s water damage or mold around the unit, that’s a job for a restoration company. See why your house smells when the AC turns on.
- You found an active leak: call a plumber (or roofer) to stop it, and a water damage restoration company to dry the walls, floors and cabinets so the smell doesn’t come back.
- You can’t find the source, or you suspect mold: call a company with Florida-licensed mold professionals that can check for hidden moisture. We offer a free visual inspection with moisture readings and an infrared (thermal) camera; lab testing is separate if it’s needed. Florida licenses: Mold Assessor MRSA4035, Mold Remediator MRSR4158.
- The source is fixed and dry, but it still smells: call an odor removal company. Our $997 whole-home odor removal treatment covers the entire home, one AC system and an attached garage. See odor removal service: what it costs and who to call.
- You rent: report the smell to your landlord or property manager in writing, with photos of any stains or water.
Get Help in South Florida
Not sure what’s causing the smell? Request a free visual inspection with moisture readings and an infrared (thermal) camera. Source already fixed? Our Whole-Home Odor Removal Treatment is $997 and includes one AC system ($550 for each additional AC unit), and you can buy and schedule it online. Call 877-224-2532. We answer 24/7, and hablamos español.
Want us to handle it? See how our musty smell removal service in South Florida works, from the free visual inspection to fixing the source to the whole-home odor treatment.
About the author: James Rice-Peña is the owner of FL Cleanup and a Florida-licensed Mold Assessor (MRSA4035) and Mold Remediator (MRSR4158). He has worked in property restoration in South Florida since 2012, and FL Cleanup has earned 200+ five-star Google reviews.
