A building is dry when its materials read at the dry level for each material, not when the surface looks dry. Moisture meters measure the water in framing, subfloors, insulation and other materials, and the drying log records each reading so the progress can be checked.
Key takeaways
- The surface of a room can look dry while the framing and subfloor behind it still hold water.
- Each material has its own dry level, so readings are compared with the target for that material and with dry areas nearby.
- A drying log shows readings, dates and equipment on each visit, and it is the record an insurer will use.
- Equipment stays in place until the readings reach the dry level, not until the calendar says it is time.
- A reading that rises again after equipment is removed means the material was not dry, and the work is not finished.
- A thermal camera shows temperature differences that can suggest wet material, but it is checked against meter readings.
Why does a dry surface not mean a dry building?
Because water moves into materials below the surface and stays there. Drywall, flooring and paint can dry at the face while the framing, subfloor and insulation behind them still hold moisture, and that moisture is what the readings measure.
Water soaks into the material it touches and travels along the framing. A wall can look dry on its face while a stud, a plate or the insulation in its cavity is still wet. A floor can feel firm while the subfloor under it is holding water.
The only way to know is to measure inside the material. That is why a crew takes readings in the framing and the subfloor, and why the look of a room is not treated as the test.
How do moisture meters work, in plain terms?
A moisture meter measures the electrical or other property of a material that changes with the water it holds, and it gives a reading that can be compared from one spot and one visit to the next. The reading is a relative measure, so it is compared with a dry reference and with the same material in a dry area.
Different meters work in different ways. Some are pressed onto a surface, some are pushed into a material, and some read through a surface without touching it. The technician chooses the meter that suits the material and records which type was used.
A reading on its own means little. A reading compared with the reading in a dry reference area of the same material, and with the reading on the previous visit, shows whether the material is drying.
What is a dry level, and why does it differ by material?
A dry level is the reading at which a material is considered dry for its purpose. Wood, drywall, concrete and insulation each reach dry at their own level, so a single number cannot be used for all of them.
Wood framing holds water in its core and dries more slowly than a surface board. Concrete can hold moisture for a long time and is read on its own terms. Drywall dries relatively quickly once its core is dry, but a wet paper face can mislead a reading.
The crew should explain the dry level for each material in your building, and the drying log should show the level it is working toward.
What should a drying log record on each visit?
The date and time, the readings in each material and in the air, the equipment in each room and any openings made. The log should also show the dry level for each material and the readings on the previous visit, so the trend is visible.
A log without locations is hard to follow. Each reading should say where it was taken, so a falling reading in one spot can be compared with the same spot on the next visit.
The log should note when equipment was moved or turned off, and why. A gap in the record is a question an insurer will ask, so it should be explained at the time.
- The date and time of each visit
- The readings in each material, with its location
- The readings in the air, and the room conditions
- The equipment in each room, and any changes made
- The dry level for each material, and the reading on the last visit
Why is equipment kept running after a room looks dry?
Because the materials behind the surface are still holding water. Removing the equipment early can let that moisture rise back into the room, and it can leave a wall or floor closed up over damp framing.
A reading that rises again after equipment is removed means the material was not dry, and the drying is not finished. Equipment should stay until the readings in the framing and subfloor have reached the dry level, and the readings have held there.
If you want the equipment removed sooner, ask the crew what the readings show and what the risk would be. The decision should be recorded, with the reasons.
What does a thermal camera add, and what can it not do?
A thermal camera shows differences in surface temperature, which can suggest where a material is wet, because wet material often cools differently from dry material. It cannot confirm a leak on its own, and its picture is checked against meter readings.
Cold walls, draughts, insulation and sun on a surface can all produce patterns that look like water. The camera is useful for narrowing the search, and it helps show where to take meter readings.
A crew should not call a leak or a wet cavity from a camera image alone. The result is confirmed by readings and, where needed, by a small opening in the material.
How do readings help with an insurance claim?
Readings show what was wet, where it was, when it reached the dry level and how the drying progressed. An insurer can use them to see whether the drying was needed and whether it was finished before repairs began.
Keep the readings with the drying log, the photographs and the scope. A complete set of readings is far more useful than a summary that says the building is dry.
The readings do not decide the claim. The insurer decides the claim under the policy, and the readings are part of the evidence it weighs.
What makes a reading drift when nothing has changed?
Readings can move with temperature, with the surface being measured, with how firmly a meter is pressed and with the condition of the material. A reading that moves without an obvious reason should be checked against a second reading and against the dry reference, not accepted or dismissed on its own.
Surface conditions matter. A damp film on a surface can read higher than the material beneath, and a surface that has been painted or sealed can read differently from bare material. The crew notes the surface and the method, so a later reading can be compared on like terms.
Temperature and humidity in the room also affect what the readings mean. The air readings in the log are there to show the drying conditions, and they help explain a reading that moved for a reason that had nothing to do with water in the material.
Why does the air in the room matter to the drying?
Air carries moisture away from materials when it is moved and when it can take up water. A room that is closed and humid can hold moisture in the materials, and a room that is open and moving air dries more readily. The drying plan sets the air to suit the room.
Dehumidifiers take water out of the room air, and air movers carry air across the surfaces. Each does a different job, and the drying plan balances them. Running only one of them is rarely the right answer.
Ask the crew to explain the air readings on each visit. If the room is closed up or heated in a way that affects the drying, the plan should say so, and the log should record the change.
Why is a dry reference reading taken?
A dry reference is a reading taken in a material of the same kind that the water did not reach. It gives the crew a baseline for what dry looks like in that building, so the wet readings can be judged against something real rather than a number from a chart.
Materials vary from one house to the next, and a reading that is high in one wall may be normal for that material in another. The reference reading makes the comparison local, and it is taken on the first visit so it is available for every visit after it.
Ask the crew where the reference was taken and what it read. If the building has no dry area of the same material, the crew should say so and explain how it judged the readings instead.
What can I ask at each visit?
Ask for the readings and where they were taken, what has changed since the last visit, what is still wet, what the crew expects on the next visit, and whether anything has been moved or turned off. Those five questions cover most of what a homeowner needs to follow the work.
Asking the same questions on each visit makes the progress easy to follow. A written answer is better than a verbal one, and a short note in the log is enough for most visits.
If an answer does not make sense, ask again in plain terms. A crew should be able to explain the readings to someone who is not a technician, and the explanation should be written into the record.
Frequently asked questions
How do I know when my house is dry?
When the readings in the framing, subfloor and cavities reach the dry level for each material, and they stay there on the next visit. The surface alone is not the test.
Why does the floor still feel damp after it was dried?
Moisture may still be in the subfloor or the joists below, even if the surface feels dry. Ask the crew for the readings under the floor, and keep the drying going until they reach the dry level.
Can I check the readings myself?
A homeowner can ask to see the readings and their locations on each visit, and can ask the crew to explain them. Measuring well takes training and the right meter, so leave the readings to the crew.
What does a rising reading mean?
It can mean water is still moving into the material, that the material was not dry when the equipment was removed, or that a new source has appeared. Call the crew, and ask what the rise means for the drying.
Why does the crew not just trust the thermal camera?
Because a camera shows temperature, which many things can change. The picture is useful for finding where to measure, but the readings are the test of whether the material is wet.
Should I open windows to help the drying?
Ask the crew before you do. Opening a window can add humid air in some conditions and slow the drying, and the crew will set the air to suit the room and the weather.
Can a reading tell me whether mold is growing?
A moisture reading shows how much water a material holds, not whether mold is present. Mold is looked for separately, with a visual check and its own readings, and the mold guide explains what to ask for.
This guide is general information for Sedgwick County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.