Florida's Hidden Moisture Problem
Florida homes face rain, humid outdoor air and strong sun while air conditioning keeps interiors cool. Moisture can enter through leaks, air movement or vapor moving through materials. When moist air contacts surfaces inside walls or roofs at or below its dew point, condensation forms. If wet materials cannot dry, moisture can accumulate out of sight.
The scale of the risk exposure
Important distinction
These numbers show the size of the exposed building stock. They do not mean that millions of Florida homes already have confirmed hidden moisture damage. No credible statewide database currently provides that count.
What Florida research shows
Negative pressure was common
In an FSEC field study of 70 central Florida homes, 64 developed negative pressure in the central zone when interior bedroom doors were closed.
Infiltration increased
In the same study, tracer-gas testing found infiltration increased 33% when interior doors were closed and the air handler was operating.
HVAC sizing practices varied
In a survey of 489 Florida A/C contractors, 33% reported using Manual J while 24.2% reported sizing systems by square footage.
Why this matters
Wet cladding can drive moisture inward
Stucco, masonry and concrete block can absorb rainwater. Solar heating after a storm can increase inward vapor drive toward cooler interior materials.
Cooling is not the same as dehumidifying
Oversized equipment can cool the house quickly while providing less runtime for latent moisture removal. Temperature alone does not tell you whether the building is dry.
Air pressure can move moisture
Duct leakage, closed rooms and pressure imbalances can draw hot, humid air through walls, ceilings and other concealed building cavities.
The four questions that matter
Before you buy, renovate, repair or sell, understand how the building manages moisture.
The objective is not to declare every Florida home defective. It is to identify moisture pathways early—before hidden conditions become expensive repairs.