How does a technician know when materials are dry?
A technician compares the moisture in each material with a dry reference reading taken from unaffected material in the same building. Drying is finished when the wet material reads close to that reference, not when it feels dry to the hand or looks normal to the eye.
Moisture meters are used on the surface and inside the material where the meter can reach. The reading is recorded with the location, the date and the time, so the same spot can be checked again. A surface that has dried can still hold water inside, and this is why the readings are taken inside the wall as well as on the face of it.
The dry reference is a practical tool and not a universal number. It is taken from the same kind of material in the same building, which is why the technician looks for a sound area to measure against before the drying starts.
Why does drying take several days?
Wet materials give up water slowly, and the rate depends on the material, the air and the depth of the wet area. A wall cavity or a thick subfloor can take several days to reach the goal, and rushing the equipment only leaves moisture trapped inside.
The air around the wet material can only hold so much water before it stops taking any more. The dehumidifier lowers the moisture in the room air so that the air can take water from the material again. That is why the equipment has to run continuously, and why it is not switched off overnight without a reason.
Drying is also paced by the building. Heavy framing, closed cavities and thick wood hold water longer than drywall or a thin floor. The technician plans the time from what is wet and what it is made of.
What should I keep out of a room while it dries?
Keep belongings, rugs and furniture away from wet walls and floors, and do not block the air movers or the dehumidifier. Items that were wet should be moved out so that the surface beneath them can dry, and they should be photographed before they leave the room.
Furniture that sits on wet carpet or against a wet wall traps moisture under it and holds the damp in. Moving it out is a quick task that saves a lot of drying time, and it also keeps the belongings from developing a stain or odor that is hard to remove later.
Doors to the drying rooms can be left closed so the air stays where it is needed. The equipment should not be covered or moved without telling the technician, because a change in the air path changes the readings.
What does the drying log show?
The drying log lists each room, each wet material, each reading and the dry goal. It shows where the moisture was when the crew arrived and when each material reached the goal, so a repair can be planned on materials that are proven dry.
The log is written for you as much as for the technician. It can be shared with an insurer, a repair contractor or a building inspector. It records what was removed, what was opened and what was left in place, which is the information that is hardest to reconstruct after the walls are closed.
A log that shows one reading per room is not enough to show the drying worked. The useful log shows the first reading and the last reading for each material, with the dates between them.
What does drying cost?
This site does not publish prices, and no figure is given on the phone. The cost of drying moves with the number of rooms, the number of materials that are wet, how many cavities must be opened and how many days the equipment runs. The estimate is explained on site and approved before any equipment is set up.
Drying is charged for the equipment and the time it runs, and for the labor to measure and open the materials. A room that needs a cavity opened costs more to dry than one that dries from the surface. A building where the water spread through several rooms costs more than one room alone.
Ask for the scope to be written down in plain terms before the work starts, with the rooms, the materials and the goal. That written scope is the basis for the price, and it is the document to compare if the drying runs longer than expected.