Use the moisture meter for walls correctly
Damp walls are a problem, which is why moisture meters for walls make sense because they allow you to detect moisture at an early stage. But you have to use them properly.
How moisture meters work for building materials and air
Moisture meters for walls work on a different principle than those used to measure air humidity:
- Hygrometer that the humidity Measure the room air, usually contain a test substance that is more or less wet depending on the humidity of the room air. This test substance has certain properties depending on the humidity, for example the length of the hair hygrometer of a hair depending on the water content or weight changes are recorded because the wet substance is heavier than the dry.
- Some hygrometers also measure the electrical conductivity of the test substance, which depends on the humidity. These hygrometers all have an integrated test medium and therefore work precisely and evenly.
- A wall moisture meter always works on electrical conductivity, but these measure the conductivity of the wall material. You do not have a neutral test medium and are therefore only accurate if you know the composition of the wall and enter it into the device.
- It is very important how exactly you can enter the moisture values of the wall and whether you know the composition of the wall. Some building materials are excellent conductors even when dry and thus signal a high level of moisture, even though it is not available.
Using the moisture meter for the wall correctly - this is how it works
Too much moisture in the wall is not only a health risk, but ...
Correct measurement with hygrometers for walls
With these moisture meters, the measurement is made by two electrodes that you either press firmly against the wall or insert into small drill holes that you have made in the wall.
- Study the manual that came with the wall moisture meter and set the correct building material from which the wall is made. Measure in places that are clearly dry and in places that are clearly wet. Compare the values. You should only rely on them for further measurements if the values determined in this way are logical.
- Measurement errors arise, among other things, from the fact that you entered the composition of the wall incorrectly, but also from the fact that walls are not a homogeneous mass. From the outside in, a wall consists of paint, exterior plaster, building materials, interior plaster, wallpaper, and paint.
- The individual layers of the wall influence each other because, for example, salts from the Inside the wall diffuse into the wallpaper and the "Paper" setting for the wallpaper then not fits. You may have to choose a different setting.
- Remember that you are measuring the moisture of the wall surface, not the core moisture of the wall, unless you drill holes that are deep enough. You can also determine the moisture of the wall surface approximately exactly if you use a board made of a known type of wood 2 Nail it to the wall days before the measurement and remove it from the wall for measurement and determine the moisture of the board.
Don't just rely on readings from a moisture meter for walls, but also pay attention to the humidity and watch the wall after heavy downpours. This also provides information about possible moisture damage and its cause.
