Mold Remediation

Humidity here does not take a break

Mold has a slow season in most of the country. It does not have one here. The Tampa Bay area averages about 74 percent relative humidity across the year, and the lowest monthly average is 69 percent, which lands in April, the driest stretch we get. EPA guidance is to keep indoor relative humidity below 60 percent, ideally between 30 and 50. Outdoor air in Pinellas County sits above that line essentially every day of the year. St. Petersburg logs muggy or worse conditions in every month, and in July it is every single day of the month.

Temperature does not do the job either. The normal low in the coolest month is 52.5 degrees and the annual mean temperature is 73.9 degrees. There is never a stretch cold enough or dry enough to stall fungal growth, which is why a small colony found in March is rarely still small in June.

Then there is the rain. St. Petersburg averages 53.62 inches a year, and nearly two-thirds of that falls between June and September. July alone brings 9.73 inches. The National Weather Service runs the West Central Florida rainy season from May 25 through October 10, and because Pinellas is a narrow peninsula with the Gulf on one side and Tampa Bay on the other, sea breezes collide inland and fire storms almost daily.

Put the three together and the practical consequence is simple: when a building material in Pinellas County gets wet, it does not dry on its own. EPA says wet materials dried within 24 to 48 hours will in most cases not grow mold. In a dry climate the ambient air does part of that work for you. Here the air does the opposite and keeps pushing moisture back into the material, which is why a leak nobody noticed for a week is usually a mold job by the time we see it.

Containment and negative air come before any demolition

The first thing that happens on a mold job is not tearing anything out. It is taking control of the air. S520, the ANSI/IICRC standard for professional mold remediation, is built around one idea: what is growing in one room should not end up in the rest of the house because somebody opened a wall.

So we build containment. That normally means poly sheeting run floor to ceiling around the work area, taped and sealed at the edges, with a zippered entry and often a small chamber where the crew changes out. Supply and return registers inside the containment get sealed, because an air handler will happily distribute spores to every room it serves. If the growth is in the air handler closet or in the duct work, the system comes out of service and gets addressed as part of the job instead of running through it.

Then we set negative pressure. An air scrubber with HEPA filtration pulls air out of the contained space and exhausts it outside, so the work area runs slightly below the pressure of the rest of the building. Air leaks in rather than out. You can watch it work: the plastic draws inward and stays there. That is what the sheeting is for. It is a pressure boundary, not decoration.

Inside that boundary the crew works in respiratory protection and disposable suits, HEPA vacuums surfaces, bags debris before it leaves containment, and cleans as it goes rather than all at the end. Anything carried out of the work area goes out wrapped.

None of this is exotic, and none of it is optional. It is the difference between a job that stays in one bathroom and a call months later from a homeowner in Seminole or Pinellas Park about a smell in a bedroom nobody ever worked in.

What actually comes out of a Pinellas block house

Construction here has its own failure points, and they decide what has to go.

Most single-family homes in this county are concrete block with stucco. Inside a block wall, the drywall is not fastened to the block. It hangs on wood or metal furring strips, which leaves a narrow concealed cavity between the two. That cavity is where water goes, and it is exactly where a surface moisture meter will not find it. The block holds water and keeps feeding it back into the paper facing of the drywall for days after the leak is fixed. That is why we cut drywall above the water line and pull baseboard on block walls instead of trusting a dry reading at the surface. Two-story homes here are often block on the first floor and wood frame on the second, so one house can need two different approaches on two floors.

Underfoot, nearly every home built from the 1950s onward is slab-on-grade. The flatwoods soils under much of Pinellas carry a seasonal high water table within 6 to 18 inches of the surface for months in a typical year, so a slab can re-wet itself from below by capillary action and vapor drive. A slab that reads dry at the surface can still ruin a floor installed on top of it.

If the house has terrazzo, the news is usually better than it looks. Terrazzo is close to non-porous and survives wetting. In 1950s and 1960s tract construction it was poured across the whole footprint before the partition walls went up, so water travels room to room underneath the walls, but the failure is normally the covering and its adhesive letting go, not the terrazzo. In older frame houses in Historic Kenwood, Roser Park or Dunedin, wet lath swells and cracks the plaster keys from behind. That work takes a slower, more patient drying schedule.

How Florida licenses mold work, and what to ask before you sign

Florida regulates mold assessment and mold remediation as licensed professions under Chapter 468, Part XVI of the Florida Statutes, administered by the Department of Business and Professional Regulation. The licensing requirement attaches at more than 10 square feet of mold. That figure is written into the statutory definitions themselves, not buried in an exemption. EPA arrives at the same line from a different direction: below roughly 10 square feet, about a three-foot by three-foot patch, EPA says a homeowner can usually handle it. Above that, both the law and the guidance agree it has stopped being a weekend project.

One detail worth knowing before you call anybody: DBPR licenses individuals, not companies. "We are licensed" is not an answer. Ask for the license number of the person who will actually be on your job, and ask which of the two licenses it is, because the state treats assessment and remediation as separate work.

It also keeps them apart deliberately. Section 468.8419 bars a mold assessor, or the assessor's company, from remediating a structure it assessed in the previous 12 months, and bars a remediator from assessing a structure it remediated in the previous 12 months. There is an exception for certified Division I contractors where the remediation contract discloses your right to request competitive bids. The plain version: the company that tells you that you have mold generally is not allowed to be the company that sells you the removal.

The statute sets insurance floors too. A licensed assessor carries at least $1,000,000 in general liability and errors-and-omissions coverage. A licensed remediator carries at least $1,000,000 in general liability that specifically includes mold-related claims, so a policy with a mold exclusion does not satisfy it. And a remediation license is not authority to rebuild. Reconstruction requires a Chapter 489 contractor license. Ask who holds that one.

Find the water first, then prove the room is clean

Remediation that does not fix the water source is a temporary result. EPA says it flatly: clean up the mold but leave the water problem, and the mold most likely comes back. So the work starts with where the water came in and whether it is still coming in. A supply line. A failed shower pan. Condensate at the air handler. Wind-driven rain pushed through soffit vents into the attic, which takes no breach of the roof covering at all and is the most common version of the storm claim where the roof still looks fine from the street.

Where the water came from matters for more than the drying plan. Storm surge is legally a flood, because the federal definition of flood covers the overflow of inland or tidal waters, and flood belongs to an NFIP or private flood policy rather than the homeowners policy. Florida hurricane deductibles are calculated as a percentage of the dwelling limit, not of the loss. Water that entered through a storm-created opening in the roof is a different conversation from water that came in at floor level. We document the water line, the entry path and the affected materials on day one, because that file is what gets read later. What your policy pays is the adjuster's decision, not ours, and we will not pretend otherwise.

S520 sorts contamination into three Conditions. Condition 1 is the normal fungal ecology of an unaffected building. Condition 2 is settled spores or trace growth with no active colonization. Condition 3 is actual visible growth, active or dormant. The goal of the job is returning Condition 2 and Condition 3 areas to Condition 1. Not "mold-free," which is not a real state for any building in Florida.

Then it gets verified. Post-remediation verification is a named part of the standard, and given the assessment firewall, that independent look is the point.