Why does a crawl space stay wet after the water has drained away?
Soil and insulation hold water for a long time, and the moist air in a closed crawl space has nowhere to go. The space dries slowly from the ground upward, so the readings can stay high after the water is gone from the surface.
Soil holds moisture below the surface, and it releases it slowly into the air of the space. A crawl space that was flooded can keep feeding moisture into the joists for weeks, even after the standing water is pumped out and the ground looks dry.
Insulation hanging under a floor does not dry quickly either. Batts that took on water and then dried partly can hold a damp core, and they keep the framing wet behind them. The crew reads the insulation and removes what it cannot dry.
What is the risk of closing up a wet subfloor?
A subfloor that is closed while it is wet can rot, grow mold and warp the finished floor above it. The floor covering can also trap the moisture and make the problem worse out of sight, which is why the readings come before the floor is closed.
Wood that stays wet over a long period is at risk of decay, and the decay is slow and hard to see from above. A floor that feels firm can have softened framing underneath, and the readings are the only reliable check.
A new floor covering on a wet subfloor traps the moisture below it. The finish can lift, cup or stain, and the framing underneath keeps the moisture that caused the problem. The subfloor has to read dry before anything is laid on top of it.
What moves the price of a crawl space drying job?
The price follows the depth of the water, the amount of sediment, the access, the size of the space and the number of readings needed. No figure is given on this site. The scope is explained and approved on site before any equipment goes into the space.
Access is one of the largest factors. A crawl space with a wide hatch is easier to work in than one with a small opening, and a space that has to be reached through a room, a garage or a closet takes longer to set up. Those points are written into the scope.
The depth of the water and the amount of sediment matter too. Clearing silt by hand in a tight space takes more time than pumping out clean water, and the crew notes the difference when it writes up the scope.
Can a homeowner check the crawl space after a storm?
A homeowner can look through the access point and note the water, the smell and the insulation, but should not go into a wet crawl space alone. The check is useful for the record, and it is not a substitute for a moisture reading.
Use a flashlight from the access point, and do not reach into the space if the water is near wiring. Photograph what you see, including the water line on the foundation wall, the insulation and any damage to the vents.
Keep a record of the time and the weather, and note whether the water is still coming in after the rain stops. That is the question the crew needs answered first.
What should be fixed before the space is dried?
The source of the water should be stopped before drying starts, or the space will keep getting wet. Broken skirting, damaged vents, a failed supply line and a grading problem outside are the common ones, and each is noted in the scope.
Some repairs belong to other trades. A plumber fixes a supply line, a licensed contractor repairs the skirting or the foundation, and the restoration crew dries the space once the source is closed. The scope names which repairs were noted, so you know who to call.
If the source is still open when the crew arrives, the crew can still drain and dry the space, but the readings will not fall until the water stops coming in. Tell the operator on the phone whether the water is still rising.
