Flood Damage Cleanup

What floodwater does to a house that sits on a slab

Water that comes in from outside arrives at ground level and stays low. It does not drip down from a ceiling; it spreads across the floor and climbs. In a typical Pinellas home — single-story, concrete block, built somewhere between 1950 and 1979, which is more than half the county's housing — the first casualties are the things nobody can see from the doorway.

Plank and laminate flooring is one. Water runs through the seams in minutes, sits on the slab underneath, and has nowhere to evaporate to because the plank above it is a vapor barrier. The floor looks fine for two days and then cups, buckles, or lifts at the ends.

Wall cavities are another. In a block home the drywall is not stuck to the block — it hangs on wood or metal furring strips, which leaves a narrow concealed gap behind the sheet. Floodwater fills that gap. A moisture meter pressed to the face of the drywall can read acceptable while there is standing water an inch behind it. That is the reason a flood job on a block wall almost always involves pulling baseboard and making a flood cut well above the visible water line, rather than trying to dry the wall in place.

Then there is everything sitting on the floor: the bottom plate of any wood-framed interior partition, cabinet kick boards, particleboard vanity bases, the paper facing on batt insulation, the ductwork if it runs low, and the bottom few inches of everything stored in a closet.

Two-story homes here are often block on the first floor and wood frame on the second, so the ground floor that floods is the one that dries slowest. The upstairs is untouched. The downstairs is a different building.

Floodwater is not clean water, and that decides what gets thrown away

Restoration work classifies water by how contaminated it is. The IICRC S500 standard, now in its fifth edition from 2021, uses three categories. Category 1 is sanitary at the source — a supply line, an ice maker. Category 2 carries significant contamination. Category 3 is grossly contaminated and can contain pathogenic or toxigenic material.

Water that came in off Tampa Bay or the Gulf, or up out of a storm drain, is handled as Category 3. It picked up whatever was on the ground on the way in: yard chemicals, fuel and oil off driveways, sanitary sewer that surcharged, dead vegetation, and the contents of every garage between the shoreline and your door. Helene put water through Shore Acres, Snell Isle, Coquina Key and Venetian Isles that had never been in those houses before, and it was not seawater by the time it got there.

One honest caveat. In March 2026 the S500 consensus body issued a position statement saying weather-related water is not automatically Category 3 by rule — the category has to be determined by gathering information and inspecting the site, not assumed from the fact that a storm caused it. In practice, on a surge or rising-water loss in this county, the inspection nearly always confirms Category 3. We still do the inspection. It decides what can be cleaned and what has to leave the building.

What generally leaves: carpet and pad, batt insulation, drywall below the flood cut, particleboard and MDF cabinetry, upholstered furniture that absorbed water, and anything porous the water sat in. What generally stays: block, framing lumber that can be cleaned and dried, tile, terrazzo, solid wood cabinetry in many cases, and hard-surface contents. Everything removed gets documented before it goes, because you will need that record later.

Drying a block-and-slab house in 74 percent humidity

Drying is where Florida flood work diverges hardest from the textbook. Three things work against you here at once.

The first is the slab. Pinellas flatwoods soils — Myakka, Immokalee, EauGallie, Wabasso, Pinellas — carry a seasonal high water table within six to eighteen inches of the surface for one to several months in a normal year. That is groundwater sitting against the underside of the concrete. On homes built before under-slab vapor barriers were routine, and the county's median build year is 1976, the slab pulls moisture up by capillary action and vapor diffusion whether or not it flooded. A slab can test acceptable at the surface and still push enough moisture to delaminate an adhesive or buckle a wood floor installed on top of it days later.

The second is the air. Relative humidity in the Tampa Bay area averages about 74 percent across the year and never drops below a 69 percent monthly average, even in the driest stretch. The EPA recommends keeping indoor relative humidity below 60 percent. Outdoor air here is above that essentially every day, which means you cannot dry a house by opening the windows. Drying has to be done inside a controlled envelope with dehumidification doing the work.

The third is the materials. S500 calls specialty drying of low-permeance, low-porosity assemblies a Class 4 loss, and lists exactly what Pinellas is built from: masonry, plaster, hardwood, lightweight concrete. Block holds water and feeds it back to whatever touches it. Terrazzo is a specific local problem — in 1950s and 1960s tract houses it was poured across the whole footprint and ground smooth before the partition walls went up, so water travels room to room underneath the walls and the floor cannot be sectioned off. The terrazzo itself usually survives. What fails is whatever was glued on top of it.

Which policy pays: flood or homeowners

This is the question that decides the money, and most people find out the answer after the loss instead of before it.

Federal regulation defines a flood to include the overflow of inland or tidal waters. Storm surge is tidal water. That makes surge a flood loss, not a wind loss, and a standard Florida homeowners policy excludes flood entirely. Flood coverage comes from a separate NFIP policy or a private flood policy. A homeowners policy covers sudden and accidental water from inside the building envelope — a supply line that lets go, an appliance that fails — and rain that enters through an opening the windstorm itself created. That last clause is the whole fight after a hurricane: the same wet drywall is a covered wind loss if the roof or a window opened first, and an excluded flood loss if the water came in at the slab. Which is why we photograph the water line, the entry path and the exterior on day one, before anything is torn out.

Things worth knowing before you need them. NFIP residential limits are $250,000 on the building and $100,000 on contents, bought separately. An NFIP policy does not pay for temporary housing; homeowners policies typically do. New flood policies carry a 30-day waiting period, so you cannot buy coverage with a storm in the Gulf. Florida hurricane deductibles are a percentage of the dwelling limit, not the loss — five percent on a $400,000 limit is $20,000 — and they apply once per calendar year per insurer group, not per storm. Florida property insurance claims are barred unless reported within one year of the date of loss, and for a hurricane that clock starts at landfall, not at discovery; an NFIP flood claim runs on its own policy's proof-of-loss terms instead.

We do not adjust claims or promise what a carrier will do. We document.

After the water: mold, the 50 percent rule, and the rebuild

A flooded house has two clocks running. The EPA's guidance is that wet materials dried within 24 to 48 hours will, in most cases, not grow mold. In a climate where St. Petersburg records muggy or worse conditions in every month of the year and the monthly normal low never falls below 52.5 degrees, there is no season that arrests growth for you. Nothing here dries on its own.

If mold does establish, Florida regulates the work. Chapter 468, Part XVI licenses mold assessors and mold remediators as individuals, not as companies, and the license requirement attaches to jobs over ten square feet — roughly a three-by-three patch, the same threshold the EPA uses for when a homeowner should stop doing it themselves. Florida also keeps the assessor and the remediator apart: a company that assessed a structure generally cannot remediate it for twelve months, and the reverse, with a carve-out for certified Division I contractors who disclose your right to request competitive bids. Ask for the license number of the individual on your job. The governing standard is ANSI/IICRC S520, fourth edition 2024, and the goal it sets is returning the affected area to Condition 1, normal fungal ecology — not "one hundred percent mold-free," which is not a thing.

The other clock is FEMA's. If repair costs reach 50 percent of the structure's pre-damage market value, substantial damage rules apply and the building has to be brought into floodplain compliance, usually meaning elevation, relocation or demolition. That is measured against the depreciated value of the structure only, not the land, which is why it lands hardest on older, modest homes on valuable lots. Largo, Dunedin and the county all ran substantial damage assessments after 2024. Scope matters. So does an accurate, itemized record of what the repair actually costs.