The first mold most Tallahassee homeowners find is not in a bathroom. It is on the back wall of a bedroom closet, behind a dresser or a headboard, or in the corner behind a couch, and it is nearly always on an exterior wall. Shoes on the closet floor get a dusting first, then the paint speckles, and by the time the closet smells the drywall has been damp for weeks.
The wider summer picture, AC sizing, attic ducts and crawl spaces, is in the earlier post on summer humidity.
Why the closet goes first
Three things line up. The air in a closet does not move: the door is shut and the clothes are packed in. The back wall is an exterior wall, and in summer the outside air here is humid enough that a wall the air conditioner has cooled sits below that air's dew point. Outside air leaking into the wall cavity meets the cool back of the drywall and condenses there; the paper face wets from behind, and the still air on the room side never dries it.
And nobody looks: a bathroom ceiling gets seen every day, the wall behind a dresser when the dresser moves.
Surface mildew or growth in the wall
A light dusting on shoes, paint or leather is surface growth feeding on the room's humidity. It wipes off with a detergent cleaner and stays off once the humidity comes down. That is a cleaning job, and the crew says so.
Growth that has reached the drywall looks different. The stain comes back within weeks of cleaning. It runs in a band along the bottom of the wall or up an exterior corner. The drywall is soft under a thumb, or a meter reads wet on that wall and dry on the interior wall opposite.
Size matters in Florida. Chapter 468, Part XVI of the Florida Statutes defines mold assessment and remediation as work on growth of greater than 10 square feet, roughly a three-foot by three-foot patch. Under that, a homeowner can clean it; over it, the work falls under the state's mold licensing law. A band two feet high along the back wall of a six-foot closet is already past the line, and the cavity side is usually larger than the surface shows. The same law bars an assessor from remediating a property it assessed within the previous twelve months, so a bigger job has two appointments.
What to fix first
Fix the air before the wall, or the wall grows back. In order:
- Bring the humidity down. The EPA and the Florida Department of Health both say below 60 percent, and lower is better; aim for around 50. A hygrometer in the closet tells you where you are; a portable dehumidifier in the bedroom brings one closet into range.
- Move the air. Leave the closet door open, or fit a louvered door so air passes through when it is shut.
- Pull furniture a few inches off exterior walls.
- Thin the closet so air reaches the back wall and the floor.
- Check the air conditioner. A unit that runs in short bursts cools the house without drying it; ask the HVAC contractor about run time and sizing, or a dehumidifier on the system, and have the condensate drain line cleared, because a clogged line overflows into the air handler closet.
- Do not paint over it. Paint on a damp wall fails within a season and hides the reading the inspection needs.
What the inspection finds in a Tallahassee closet
A visual inspection with moisture mapping runs $150 to $300 on this line; one with air and surface samples and a written protocol runs $300 to $700. Sampling is for growth that is hidden, spread across rooms, or tied to a claim; for one closet with a visible patch, the moisture map is usually enough.
The meter reads the closet's back wall against the interior wall beside it; the difference says whether the wall is wet or the room is just humid. The thermal camera shows the cold band along the base of an exterior wall, or the spot where a supply register blows at the closet wall through an open door. The inspection also covers the air handler closet, the attic above a stained closet ceiling for a duct that has lost its insulation, and, in Midtown, Betton Hills and Indianhead Acres, the crawl space under the floor.
When it becomes a remediation job
If the meter reads wet through the drywall, or the growth is past the 10-square-foot line, the closet is a small remediation: under 100 square feet, $1,000 to $3,000 for one wall cavity. The doorway is sealed with plastic, a HEPA air scrubber runs, the bottom section of drywall and the wet insulation come out, the studs and bottom plate are cleaned, and the cavity is dried until the wood reads dry. Then the wall is closed, and the scope names what changes about the air so the crew is not back next August.
The written scope sets the square footage and the price before anything is cut; if the cavity is wetter than the surface showed, the change is written down and priced before work continues. If symptoms in the house persist, see a doctor.
Useful links
- EPA: a brief guide to mold, moisture and your home – humidity below 60 percent, the 10-square-foot line
- Florida Statutes, s. 468.8411: mold-related services definitions – assessment and remediation defined for growth of greater than 10 square feet
- UF/IFAS Extension: mold management in the home – Florida extension guidance on humidity and keeping closets open until they dry
Questions on this
Why does the closet on the north side of my Tallahassee house grow mold every summer?
The north wall gets the least sun, the air conditioner keeps its inside face cool, humid outside air leaking into the cavity condenses on the back of the drywall, and a packed, closed closet never lets it dry. A dehumidifier, a louvered door and a gap behind the clothes fix most of them.
Can I clean closet mold in Tallahassee myself, or does Florida's 10-square-foot rule apply?
Under about 10 square feet, roughly three feet by three feet, you can clean it with a detergent cleaner; the EPA and the Florida Department of Health both say so. Above that the work falls under Florida's mold licensing law. If the drywall is soft or reads wet, book the inspection before cleaning.
Will a closet remediation in Tallahassee need an assessor as well as the crew?
Not for one closet with a visible patch and an obvious cause; the scope can be written from the moisture readings. If the growth is hidden, has spread to a second room, or is tied to an insurance claim, an assessment with lab samples and a written protocol comes first, and under Florida law the assessor and the remediator are separate companies.