What an independent inspection actually turns up.

Fort Pierce, St. Lucie County

Ceiling discolouration in a beachside condo — the air handler was the source

Property

Beachside condominium, Hutchinson Island

Why they called

Recurring dark discolouration on bedroom ceilings and around supply registers

What the inspection found

Indoor relative humidity at 63% — above the 55% ceiling where growth stops being sustainable. Very poor duct cleanliness, a small plenum air leak, water damage with an active leak at the air handler, and visible microbial growth on HVAC-related surfaces. Black discolouration, ghosting, and darkened registers appeared in the bedroom and elsewhere in the unit, indicating a building-system problem rather than one isolated patch.

Moisture source

HVAC. An actively leaking, improperly installed air handler combined with sustained high humidity and condensation on cooled surfaces — not roof or plumbing intrusion.

Recommendation

Physical remediation of the affected materials rather than encapsulation or paint-over, replacement of visibly affected materials so secondary moisture pathways were not left in place, and evaluation of the air handler installation by a licensed HVAC contractor. Humidity control was the precondition for any of it holding.

Laboratory sampling performed

Boca Raton, Palm Beach County

Called out after a neighbour's mold scare — the honest answer was no mold problem

Property

Two-storey single-family, roughly 20 years old, three air handlers

Why they called

A neighbour's house had turned out to be full of mold. The owners had no odour and saw nothing, but had a history worth checking: an old sprinkler leak at the baseboards, a toilet overflow two years earlier, and mold previously found in an air handler that had since been replaced.

What the inspection found

No active mold problem anywhere in the house. The bathroom with the prior overflow was clean and dry on both visual inspection and thermal. What the inspection did find were four unrelated moisture issues, none of which had produced growth yet: an actively leaking reverse-osmosis unit under the kitchen sink, several supply registers condensating because the boots were never sealed to the attic, an unsealed exterior hose-spigot penetration pushing rainwater into an office wall, and a minor stain on a garage ceiling below an isolated roof section.

Moisture source

Four separate small sources rather than one event. The register sweating was attic air leaking past unsealed boots and condensing on cold metal. The office wall was rainwater entering through an unsealed stucco penetration — it had also soaked an outlet and tripped the breaker behind a television the owners assumed had died. The garage stain pointed to a minor roof or gutter-flashing leak.

Recommendation

No remediation recommended, and no sampling performed — neither would have changed anything. The fixes were a drip pan under the RO unit, spray foam at the register boots, a tube of caulk at the spigot penetration and window sills, and a roofer to look at the garage ceiling. Most of it was work the owners could do themselves for the cost of the materials.

No sampling — it would not have changed the recommendation

Mold spreading through a flight school — the cause was a thermostat setting

Property

Commercial flight-training facility, built 2019, six to eight air handlers, drop-ceiling plenum

Why they called

Mold appearing in scattered places with no obvious water source — under tables and chairs, on the backs of picture frames, around air vents. A musty odour in one classroom, and staff reporting coughing whenever the air conditioning ran.

What the inspection found

Thermostats across the building had the fan set to ON rather than AUTO. With the fan running continuously, the air handler pulls moisture out of the air while cooling, then blows it straight back into the room once the compressor cycles off — driving humidity up throughout the building. An ATP surface swab returned 1,464 RLU against a 0–30 clean threshold. Air handler two was leaking at the condensate P-trap, air handler five had a hole in a duct near the exterior wall, and microbial load had settled across dust in the plenum. An earlier roof leak had already been repaired and was not active.

Moisture source

The HVAC fan setting, primarily — mechanically forcing moisture back into occupied space. Compounded by the condensate leak, the duct breach, and residual humidity left in the plenum by the earlier roof leak. No active water intrusion was found anywhere in the building.

Recommendation

No formal remediation required. Every thermostat set back to AUTO on the spot, at no cost — that alone addressed the mechanism. Then service all air handlers, clean and seal the ducts, fog the plenum, wipe down the surfaces with visible growth, and replace or seal the water-stained ceiling tiles. Scattered mold with no visible water source is a humidity problem until proven otherwise, and humidity problems usually trace to the equipment.

Laboratory sampling performed