Water Damage Restoration Fundamentals

Relative humidity is relative to temperature, so the same RH% means very different amounts of water at different temperatures. Take RH and temperature together to calculate GPP (grains per pound), the foundation every other drying decision in this course builds on.

Real moisture-inspection scenarios from actual jobs — the dry-standard check, and when a wet wood or concrete subfloor means you pull the flooring instead of drying through it.

Real extraction scenarios from actual jobs — pulling bulk water off hard flooring and carpet, then pulling, cutting, bagging, and hauling out a soaked carpet pad on a CAT job.

Floating a carpet to dry the wood or concrete subfloor, after the wet pad is out, takes less air power than most techs reach for by instinct — too much CFM whips the carpet and stresses the softened latex backing. The right horsepower, the corner-release setup, and the inspection check that catches delamination before it becomes a claim.

An empty outlet doesn't mean an empty circuit. Real amp draw numbers for restoration equipment, extension cord gauge and length, GFCI protection in wet environments, and the ten-minute stabilization watch before you leave a site.

When a water loss goes unchecked long enough to turn a whole structure into a mold problem, you work from an independent third-party protocol, not a guess — lead checks before demo on old homes, outside-exhausted negative air, stripping plaster and lath to expose the full scope, matching your source-removal method to the depth of growth, and an independent clearance before the final seal goes on.

Any surface sitting at or below the room's dew point will condense, creating new wet spots on materials the original loss never touched. Dew point depression tells you which surfaces are about to become your next problem.

Air mover counts come from a real calculation: one per room, plus a ratio of affected floor area, plus an extra unit for every inset — and that calculation doesn't change by Class of loss.

Dehumidifiers are sized by room volume. The AHAM rating on the box is a lab number, but the formula already accounts for that, so match your calculated pints to the rating. And know when desiccant sizing applies instead.

Mold begins in wet material, fastest in dead-air pockets with no airflow — behind furniture, baseboards, and inside wall cavities. An open-room reading that looks fine can still be hiding the real problem.

Grain depression — the GPP difference between a dehumidifier's intake and exhaust — is a field check of whether it's still pulling water, not the pint rating on the box. Grain depression naturally falls as the air dries, and your drying target is always the moisture content of the materials.