Water comes out of a flooded house before drying begins, because drying equipment cannot remove standing water. After extraction, the walls, floors and framing are dried to measured targets. Drywall, insulation and carpet are removed when readings show they cannot dry in place or when the water has contaminated them.
Key takeaways
- Standing water is removed first, because drying equipment cannot remove a pool of water.
- Drying is measured against dry readings from unaffected materials, not timed by a fixed number of days.
- Drywall is removed where the readings show moisture inside the wall and the board cannot dry in place.
- Insulation that holds water is removed, because it keeps the framing wet for a long time.
- Hard floors can often dry in place, while carpet pad that stood in flood water is usually removed.
- A finish should not be replaced over a wall or floor until the readings show it is dry.
Why must the water come out before drying starts?
Drying equipment pulls moisture from materials and air, but it cannot remove water that is standing on a floor or in a pool at the base of a wall. While the water is there, it keeps soaking the materials and raising humidity. Extraction removes the bulk water first, so the drying works on the structure.
A room with standing water is still being fed by that water. Air movers placed in it move moisture around the room, and the materials under the water keep taking it in. The crew extracts from the lowest point outward so that the water is not pushed into a clean area.
Once the water is out, the crew reads the floor, the carpet and the lower walls. Those readings show where the moisture is still held, and they decide where the equipment goes. Skipping extraction to start drying sooner almost always makes the drying take longer.
How does the drying equipment work on walls and floors?
Air movers push air across wet surfaces to speed evaporation, and dehumidifiers condense moisture out of the air. Together they carry moisture from the material into the air and out of the room. The equipment is placed by the readings and moved as they change.
Air moves across a wall or floor and carries moisture away from the surface. Without airflow, the air at the surface becomes saturated and stops taking moisture from the material. That is why air movers are placed so their air crosses the wet surfaces, and not only the open floor.
The dehumidifier pulls the water out of the room air, which lets the materials keep releasing moisture. The equipment does not warm the house to dry it, and the crew adjusts the layout as the readings change so the drying reaches the places that still read high.
When should drywall come out?
Drywall is removed when the readings show moisture inside the wall that cannot dry in place, when the board is soft or crumbling, or when the water was contaminated enough that the board cannot be kept. A cut is made only where the readings show the need, and it is photographed before it is made.
Drywall is paper and gypsum, and it wicks water from the bottom. A board that stood in flood water to a height of a few inches can hold moisture above that line, and the framing behind it can stay wet. A reading taken inside the wall shows how far the wetness went.
A drywall cut is made high enough to show the wet area and low enough to reach the bottom plate. The crew keeps the cut as small as the readings allow, and it records the height of each cut so the repair can be matched to the old wall.
| Material | Usually kept when | Usually removed when |
|---|---|---|
| Hard flooring such as tile or sealed concrete | The surface and edges read dry after extraction | Water has lifted it or the subfloor beneath holds moisture |
| Carpet and pad | The carpet was dry and never reached the water | The pad stood in flood water or stays wet to the readings |
| Drywall | The board reads dry behind the face and is still intact | Moisture is inside the wall and the board is soft or crumbling |
| Insulation | The batts are dry above the water line and read dry | The batts or loose fill are wet and cannot be dried in place |
| Framing and subfloor | The readings fall to the dry reference | The wood has rotted, lost strength or will not reach the reference |
When should insulation come out?
Insulation that has held water is removed, because it stays wet for a long time and keeps the framing damp. It is hard to clean and hard to dry in place. Insulation that stayed dry can often be kept, and the crew reads it before deciding.
Fiberglass and cellulose insulation can hold water in their fibers and between the batts. The water does not drain away, and the material stays wet long after the room looks dry. A wet batt also sags and loses its ability to insulate once it has dried.
The crew removes insulation that reads wet and records the quantity and the wall it came from. Dry insulation above the water line is checked separately, and it is kept when the readings show it has not taken water.
A homeowner who wants to save a hard floor should ask the crew to lift a sample of the edge and the gap under the baseboard. Boards that cup only at the edges often flatten as they dry, while boards that have lifted from the subfloor usually need replacing. The sample shows which case applies before the whole floor is decided.
How are floors dried?
Hard floors such as tile, concrete and sealed wood can often dry in place once the water is out and the readings are taken. Carpet and pad that stood in flood water are usually removed, because the pad holds silt and moisture. The subfloor is read in either case, and it is dried before the floor is closed.
Hard floors dry from the surface and from the edges, and the crew checks the gap under the baseboard and the grout lines. A floor that looks dry can still have water under a tile or in the joint, so the readings and a look at the edges decide when it is finished.
Carpet is lifted and the pad removed when it has taken flood water, and the subfloor beneath is read and dried. The crew records which sections were removed and why. Carpet that was dry and was not in the water can sometimes be dried in place.
How do you know a wall or floor is dry?
A material is dry when its reading matches a dry reference taken from an unaffected part of the house. The crew compares each reading with that reference and records the result. A surface that looks dry but reads wet is not dry, and drying continues.
A moisture meter gives a reading for each material, and the reference reading comes from a dry area of the same house. The reading that matches the reference is the target. Materials that stay above it are still holding water, and the crew keeps drying them.
The final check looks at the framing, the subfloor, the lower wall and the floor edge, not only the finished surface. The crew records the readings on the map of the house, so the homeowner can see every area that was checked before the finish is replaced.
Why does drying sometimes stall?
Drying stalls when a source is still feeding water, when a cavity has not been opened, when a material is still wet beneath the surface or when the air path does not reach the wet area. A reading that does not fall between visits is a signal to look for one of these, not a sign that the process has failed.
The most common cause of a stall is a wall cavity or a floor space that holds water and was not opened. The surface reads dry, but the framing and insulation behind it stay wet. Opening the cavity at the highest reading is usually the fix.
A second cause is a source that is still active, such as a loose fitting, a drain that is blocked or a window well that keeps filling. The crew checks for the source before adding more equipment, because more equipment cannot dry a space that is still being wetted.
What should a homeowner avoid while the house is drying?
Do not close up a wet wall, do not paint over a damp surface, and do not run the heat hot to speed the drying. Do not rely on household fans alone, and do not move the drying equipment while it is running. Ask the crew before you change anything in a room that is being dried.
Painting or covering a damp surface hides the moisture and can trap it behind the finish. The finish can bubble, stain or support growth later. Wait until the readings confirm the material is dry, then ask the right trade to repair the surface.
Keep children and pets out of rooms with running equipment, and keep the air intakes and exhausts clear of furniture and curtains. If a machine stops, or makes an unusual noise, call the crew so the readings can be checked and the equipment restarted correctly.
Frequently asked questions
Can I dry the walls with a box fan and a dehumidifier from the store?
A household fan and a small dehumidifier cannot remove the moisture held in framing and insulation, and they can spread damp air through the house. The crew uses equipment placed to reach the materials and reads them to confirm the drying.
Why does the crew cut a hole in the drywall that looks fine?
The drywall can look dry on the face while the cavity behind it stays wet. The crew opens a small area where the readings are highest, so the framing and insulation can be checked and dried. Each cut is photographed first.
How do I know when the drying is finished?
Drying is finished when the readings in the materials match the dry reference and the framing and subfloor are also dry. The crew records the final readings and shows them to the homeowner before the finish is replaced.
Can I keep the hardwood floor?
Solid hardwood that was flooded can sometimes be dried in place, but it may cup, warp or cloud if the water was held for a long time. The crew reads the boards and the subfloor beneath, and it explains the likely outcome before anything is decided.
Does drying count as the repair?
No. Drying removes the water and returns the structure to its dry readings. Replacing drywall, flooring and paint is the repair, and it is quoted by the trades that do that work after the drying is complete.
This guide is general information for Douglas County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.