Drying is the part of a water loss that determines whether the job worked. Extraction removes what you can see. Drying removes what soaked into framing, subfloor, plaster and concrete — and that is the water that causes mold, cupped floors and failed finishes if it is left behind.
A calculation, not a guess
Air mover count and dehumidification capacity come from the volume of affected space, the class of loss and the materials involved. A 900-square-foot finished basement with wet carpet on slab is a different load from a bathroom with a wet subfloor, and setting the same three fans in both is how jobs fail.
Air movers do not dry materials directly. They break the saturated boundary layer sitting on a wet surface so evaporation can continue; the dehumidifier then pulls that moisture out of the air. Run air movers without matching dehumidification and you have moved water from the floor into the air, where it condenses somewhere else in the house.
Readings, every day
We set a dry standard at the start by metering unaffected material of the same type elsewhere in the building. That is the target. Affected materials are then measured at fixed, marked points each day and logged with temperature and relative humidity.
Equipment stays until readings reach the standard. Not on a schedule, and not because a surface feels dry — a hardwood floor reads dry on top while the subfloor beneath it sits well above target.
Concrete and old slabs
Basement slabs in this city are often seventy years old and poured without a vapour barrier underneath. Concrete releases moisture slowly and keeps drawing it from the ground, which means a slab can hold a reading long after everything above it is finished. We meter the slab separately and, where flooring is going back down, confirm it against a moisture standard rather than assuming it is dry because the room feels dry.
The Minnesota winter problem
Outdoor air here is genuinely dry in winter, which sounds helpful and often is not. Cold air brought into a warm building does dehumidify, but drop the chamber temperature too far and evaporation slows, because warm materials release moisture and cold ones hold it. The balance of temperature, airflow and dehumidification has to be managed deliberately in January, and it is not how the same loss would be dried in July.
Drying inside assemblies
Some water sits where open-air drying cannot reach: wall cavities, under floating floors, beneath cabinets and kickspaces, inside stairwells. Rather than demolishing, specialty equipment directs airflow into the cavity through small controlled openings — injection drying for walls, mat systems for hardwood. Slower than tearing it out, and it saves the finish.
What you get at the end
A complete log: initial readings, the dry standard, daily moisture and atmospheric readings, equipment placement, and final readings showing materials at target. That is the proof the structure was dried.