Wall Moisture Meter

With a suitable wall moisture measuring device, it can be determined very quickly on site whether the walls have increased moisture values. The affected areas can then be exposed and examined more closely. If an exact measurement of the moisture content of the building material is useful or necessary, the samples can be taken from the most affected areas and dried in the kiln at the temperature recommended for the respective building material. The difference in weight between the wet and dry sample corresponds to the water content.

Rainwater penetrating through damage to the roof or facade, to balcony or terrace connections, leaky pipes, thermal bridges on external walls, rising damp from the ground, missing or poorly executed sealing of shower areas – the causes of moisture damage in buildings can be very different. Depending on the cause of the moisture penetration and the type of building construction, there is often a characteristic moisture distribution. This is not always visible to the naked eye. If the damaged area is not hidden behind tiles, cladding, furniture or fixtures, the moisture distribution in the near-surface area can be determined very quickly with a non-destructive wall moisture meter. However, in order to check how the moisture has been distributed at different depths of the wall cross-section, it is necessary either to take samples from the depths or to use the wall moisture measuring device with which long electrodes can be inserted into the component cross-section. These device models, which determine the moisture content via electrical conductivity or electrical resistance, often have various interchangeable electrodes that are pierced directly into the component or inserted into suitable holes.

Determination of the extent of the damage
There is often a suspicion that solid or drywall has become damp due to leaking water or discovered discoloration. Then the non-destructive wall moisture measuring device should first be used to check whether and in which areas the increased values occur. Even if the material and structure of the affected walls are not exactly known, the spread of the increased moisture can be determined relatively easily by additional comparative measurements on unaffected areas of similar walls. If the cause of the moisture penetration is still unknown, the distribution of the moisture often already indicates where the moisture came from. These points can then be specifically examined more closely.

Control of the drying measures
The measurements with the wall moisture measuring device can be used to ensure that wet mounted components or those that have been subsequently soaked have dried sufficiently before further work can be carried out. For this purpose, the measurements can be repeated as often as desired at the same point using the standard wall moisture meter. On the other hand, it is possible to check the drying progress by measuring the air humidity directly on the affected component. For this purpose, the hygrometer used is placed on the component to be tested and wrapped and taped with the airtight foil.

As long as the component has a humidity level that is too high for the prevailing ambient conditions, it will release moisture into the ambient air. This results in a measurably higher level of humidity under the foil than in the surrounding area. When the component has already reached the equilibrium moisture content, the air humidity under the film is the same as in the surrounding area.

Detection and prevention of moisture damage caused by incorrect room climate
Not only liquid water, but also excessive humidity, which is not reduced quickly enough, can lead to moisture damage and mold formation on the components. The moisture that the air can no longer absorb not only settles on surfaces, it also penetrates into absorbent components. The connection between moisture damage caused by excessive humidity and heating and ventilation behavior is now well known. However, since the high humidity is usually not consciously perceived, there are still cases in which mold develops on cold external components as a result of the use of the room.

In order to avoid the damage from moisture, many landlords provide their tenants with information material on heating and ventilation and handy measuring devices for monitoring room temperature and humidity when they move in. Most of these practical thermohygrometers have a warning function that gives an optical or acoustic alarm if the air moisture is too high. The user is automatically informed by the measuring device that the ventilation process should take place.

In the case of moisture damage to the walls, it is not always clear how the moisture penetrated the component. However, the cause can almost always be clarified by the targeted examinations. First, the wall moisture meter is used to check which surfaces have high moisture values. Then it should be clarified whether there was water damage in this area, whether the water-carrying pipes were laid there and whether water could penetrate from outside or rise from below. In some cases, the moisture penetration cannot be assigned to any of these causes and the moisture distribution corresponds to the usual damage pattern with increased air humidity. Data loggers, which record the temperature and humidity values over several days or weeks are then often applied in the rooms that are used. These values provide information about the heating and ventilation behavior. If the relative humidity is too high, the condensation appears first on the coldest surfaces. In the buildings where these thermal bridges cannot be seen with the naked eye, they can be identified by measuring the surface temperature. This can be implemented particularly quickly and practically with thermal imaging cameras, as these directly display the areas with a lower temperature. Based on these images, it is often possible to decide directly whether structural measures on this thermal bridge make sense.

Selection criteria for the wall moisture meter
Experts, craftsmen, building owners, tenants or housing managers all strive to avoid moisture damage on and in the buildings and, in the event of the damage, to quickly clarify and fix the cause. Various measuring devices can help to achieve these goals. Below are the most important criteria that should be considered when it comes to choosing the wall moisture meter from the multitude of devices available.

Measurands for the moisture measurement on and in the buildings
- Material moisture
- Room temperature, humidity
- Calculation of the dew point
- Surface temperatures individually or as a thermal image

Functionality in the wall moisture meter
- Non-destructive or minimal-destructive measurement
- Measuring depth fixed or variable
- Display of the measurement results with or without scale or rating - Stored characteristic curves for specific materials
   or groups of materials for which the approximate material-specific moisture content is then displayed
- Alarms for too high or too low humidity values
- Storage option for measured values
- Interfaces for data transmission

Special accessory for the wall moisture meter
- additional external humidity electrodes for different measuring depths
- additional external humidity electrodes for certain materials or measuring situations

Some device models can be used for different measurement methods. For example, there are types of the wall moisture meters and thermal cameras that also measure humidity and air temperature. However, for experts and property managers who frequently assess moisture damage, it often makes sense to purchase several special devices for different situations.

Some types of mold are cultivated to make certain types of cheese, such as camembert, or to refine salami. One species or genus – Penicillium chrysogenum (formerly known as Penicillium notatum) – is even used to make the antibiotic penicillin to treat bacterial diseases. However, most types of mold are undesirable because they decompose materials and can be a health hazard. The harmful substances can not only be ingested through infested food, but also through skin contact and by inhaling the spores.

In order for a mold species to be able to colonize new areas and spread, it must form and distribute spores. In addition, there must be sufficient nutrient substrate and moisture at the places where the spores settle so that the mold can germinate and grow.

Visible mold growth is clear evidence that spores were brought in, which found enough moisture to germinate and a suitable nutrient substrate to grow. Many mold fungi are not particularly demanding when it comes to choosing their growing medium, moldy joints in shower areas and mold on plaster and wall paints are just a few of many examples. The introduction of spores via the ambient air can only be prevented with great effort in normal living and working areas. In many cases, this leaves only the limitation of moisture as an easy way to prevent the spread of mold infestation.