Outdoor air in Lakeland is often too humid to dry a wet house for much of the year. The EPA advises keeping indoor relative humidity below 60 percent, ideally 30 to 50 percent, and drying wet areas within 24 to 48 hours where possible. Fans move air over wet surfaces, while dehumidifiers take moisture out of the air itself.
Key takeaways
- The rainy season in west central Florida runs roughly from 25 May to 10 October, and most of the year's rain falls between June and September.
- The EPA's target is indoor relative humidity below 60 percent, ideally between 30 and 50 percent.
- Drying wet areas within 24 to 48 hours is a prevention target, not a guarantee, and moisture readings decide when materials are actually dry.
- Fans speed evaporation from wet surfaces, but dehumidifiers remove water from the air, so the two do different jobs.
- Florida's mold licensing rules apply to mold areas above about 10 square feet.
- Under Florida law, the person who assesses mold should not be the person who remediates the same structure within the following 12 months.
Why doesn't outdoor air dry a wet house?
Outdoor air in central Florida carries a lot of moisture for much of the year, so opening windows often adds water to a house rather than removing it. Drying works only when the air is drier than the wet material.
The rainy season for west central Florida runs roughly from 25 May to 10 October, and its start shifts from year to year. Between June and September, 55 to 70 percent of the annual rainfall typically falls. That means the months when a leak is most likely to need drying are also the months when the outside air is least willing to help.
Evaporation slows when the air next to a wet surface is already close to saturated. A wet wall in a humid room gives up its water slowly, and the moisture it does release stays in the air and settles on cooler surfaces such as window glass or the back of a cabinet. The same leak that dries well in a dry-season month can stall in July, even with the doors shut and the air conditioning running.
What does the EPA's 60 percent target actually mean?
The EPA advises keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent. Staying under that line limits the conditions mold needs to grow on damp materials.
Relative humidity measures how much moisture the air holds compared with the most it could hold at that temperature. Mold needs moisture to grow, and damp building materials are where it starts. Keeping indoor air below 60 percent does not kill mold that is already present, but it stops surfaces from staying damp for long periods.
The EPA's guidance on wet materials points to drying within 24 to 48 hours where possible. That window is a prevention target, not a promise. A moisture meter reading on a wall or subfloor is the only reliable way to tell whether it has dried, and a structural drying job is finished when the readings say so, not when the surface merely looks dry.
Why do fans alone leave a house damp?
Fans move air across wet surfaces to speed evaporation, but they do not lower the amount of water in the air. In humid air, the moisture a fan lifts off a surface has nowhere to go but back into the room.
Air movers are useful because they keep moisture moving off the surface so it can evaporate. Their limit is the air itself. When relative humidity is already high, the air can take up very little more water, so evaporation slows even though the fan is running at full speed. A room can feel dry to the touch and still have damp wall cavities or a wet subfloor underneath.
A dehumidifier pulls moist air across a cold coil, condenses water out of it, and sends drier air back into the room. That lowers the humidity that the fans would otherwise just circulate. Standard drying practice uses air movers and dehumidifiers together, and the crew uses moisture meters and thermal imaging to find hidden water that surface checks miss.
How do slab homes in Lakeland complicate drying?
Many homes here are built on concrete slabs without basements, so water has fewer places to drain and more places to hide. A single-story floor plan spreads water across one level, and supply lines can run beneath the slab.
When a pipe leaks under a slab-on-grade house, the water has nowhere lower to go. It travels sideways under flooring, into baseboards, cabinet bases and wall plates, and sometimes up into insulation. An air handler in the attic can also sit above finished ceilings, so water from a condensate problem may appear in a room far from the source. Drying has to reach all of those spaces, not just the floor that shows the stain.
Manufactured and mobile homes make up a large share of Polk County’s housing. In those homes, water can collect in belly-board insulation and in ducts under the floor, where a fan at the door cannot reach. Those areas need to be opened, measured and dried on their own terms. A crew can cover the water cleanup and drying, but repair of the home’s structure or leveling is a separate trade.
Why did the 2024 storms make drying so slow?
Tropical Storm Debby and Hurricane Milton left inland water that took weeks, not hours, to leave. Rainfall totals and lake levels, not just the storm itself, decided how long many homes stayed wet.
Rainfall across Polk County varies a great deal in a single storm. In 2022, Hurricane Ian left about 16.99 inches at Lake Wales and about 2.4 inches at Auburndale, according to preliminary figures, and the fastest wind measured in the county, 78 mph, was recorded in Lakeland. Rain in one town and not the next is one reason a flood can hit one street hard and leave the next one dry.
In 2024, the county emergency-management director said the western part of the county received “eight or so inches” from Debby, and deputies checked more than 40 homes in west Lakeland near Cannon Street and Jensen Avenue. Milton brought 12 to 16 inches of rain across central Florida, and a sheriff’s official described historic flooding in northwest Lakeland. A city public notice said the Peace and Hillsborough rivers had been in flood stage since Debby, which meant upstream water drained slowly. Pumps and piping moved water from Lake Bonny to Lake Parker, and residents complained that the water went down painfully slowly. A home in that situation cannot dry quickly, because the air outside stays humid while the water around it stays high. For background on how the rainy season shapes these events, see the hurricane water damage guide for inland Polk County.
Why is mold a licensing question in Florida?
Florida licenses mold assessors and mold remediators through the Department of Business and Professional Regulation. Its rules apply to mold areas above about 10 square feet, and the two roles must be kept apart.
The Department of Business and Professional Regulation regulates mold-related services under Chapter 468, Part XVI, of the Florida Statutes and Rule Chapter 61-31 of the Florida Administrative Code. There are two separate license types, mold assessor and mold remediator. Anyone seeking either must pass an examination the department approves, and those examinations are given by outside organizations rather than by the department itself. The rule frames the assessor exam around mold growth over about 10 square feet, and the remediator exam around removing or treating mold of that size.
The separation matters for a homeowner. Under Florida law, an assessor may not remediate a structure it assessed in the previous 12 months, and a remediator may not assess one it remediated in that period. The practical advice is simple: the person who tests should not be the person who sells the cleanup. Ask any company for its DBPR license number and look it up on the department’s website. Mold can trigger allergy and asthma symptoms in some people, which is one reason an early assessment is worth asking about. More detail is in the mold licensing guide for Florida.
What should a homeowner do in the first hours?
Stop the water at the main valve if you can do it safely, stay out of standing water near outlets, and photograph everything before anything is moved. Drying that starts early limits how far mold can spread.
Shut off the water at the main valve first. Turn power off to the affected area only if the electrical panel is dry and safe to reach. Stay out of standing water near outlets and appliances. Then take photos and video of the damage before anything is moved, lifted or thrown out, because those images are what an insurer will ask for.
Phones are answered 24/7 and a crew is dispatched as fast as one is available. Coverage is decided by your insurer under your own policy, so check your policy or ask your agent what it covers. In general, a homeowners policy often covers sudden and accidental water damage, such as a burst pipe, and usually does not cover long-term leaks, flood or sewer backup unless an endorsement was added. A regional news report said only about 2 percent of Polk homes had flood insurance at the time of Hurricane Ian. The crew can document the damage for your claim, and can provide moisture readings and photos to share with your insurer.
Frequently asked questions
Can I just open the windows to dry my house?
Usually not in the humid months. Outdoor air in central Florida often holds as much moisture as the air inside, so opening windows can add water to the house instead of removing it. Drying works when the air is drier than the wet material, and that depends on the weather on the day. Opening windows is never a substitute for moisture readings and dehumidification.
Is 60 percent humidity a legal limit in Florida?
No, this guide does not treat it as one. The EPA presents below 60 percent relative humidity as guidance for keeping mold from growing, with 30 to 50 percent as the ideal range. Florida’s licensing rules for mold are a separate matter, and they apply to mold areas above about 10 square feet. A humidity reading above 60 percent is a reason to check the air, not proof of a code violation.
Do I need a licensed company to remove mold?
Florida’s licensing rules apply to mold areas above about 10 square feet, so the answer depends on how large the affected area is. For larger areas, a DBPR-licensed mold remediator is the required route under Florida’s rules. Ask any company which license it holds and look that number up on the department’s website. Smaller areas can still be handled carefully, and it is reasonable to ask a company to explain its process.
How does the crew know when my house is dry?
The crew uses moisture meters and thermal imaging to look for water in walls, cabinets and under floors, and rechecks readings over time. Materials are considered dry when the readings show they are, not when the surface looks dry. Photos and readings can be shared with your insurer. Drying takes as long as the materials need, and the work is not finished until the numbers say so.
Do dehumidifiers get rid of mold?
They do not remove mold that is already growing. A dehumidifier lowers the moisture in the air, which keeps damp materials from staying wet and slows further growth. Removing existing mold is a separate job, and in Florida it falls under the mold licensing rules when the area is above about 10 square feet. Lower humidity and prompt drying are the two steps that help most.
Does my homeowners policy cover water damage from a leak or a storm?
That depends on your policy and your insurer. A homeowners policy often covers sudden and accidental water damage, such as a burst pipe, but usually does not cover long-term leaks, flood or sewer backup unless an endorsement was added. Flood coverage is generally a separate policy. Check your policy or ask your agent, and call your insurer early.
Sources
- U.S. Environmental Protection Agency
- National Weather Service Tampa Bay
- National Weather Service Tampa Bay storm climatology
- Cornell Legal Information Institute
This guide is general information for Polk County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.