Building Moisture Meter / Building Material Moisture Meter

Electronic building moisture meters enable quick and uncomplicated measurements on site, which can be repeated as often as you like. In contrast to the drying method and the calcium carbide method, in which sample material has to be taken for each measurement, the measuring process with an electronic building moisture meter is very quick and non-destructive. These building moisture meters are usually very handy and easy to use. However, when carrying out the measurements and interpreting the measurement results, it is necessary to pay attention to the special features of the respective device type.

Humidity values that have been increased over a long period of time can lead to irreversible damage to the affected components on the one hand and health impairments due to poor indoor climate and the spread of mold and other microorganisms on the other. In the buildings with load-bearing wooden structures, there is also a risk that wood that has become saturated with moisture will be decomposed by certain wood-destroying fungi. It is therefore advisable to regularly check the areas at risk of moisture and, if unusually high moisture values are suspected, to measure them with the building moisture meter. If the suspicion is confirmed, the cause should be clarified and rapid drying provided.

Possible applications for the building moisture meters in the construction process
Depending on the type of the building material, its moisture content and the moisture in the environment or the substrate play a more or less important role in the storage and processing of the material and ultimately in its behavior when installed. For this reason, there are specifications for wood and wood-based materials, for example, on the permissible wood moisture content during installation. The values depend on the usual ambient conditions at the installation site, so that there is no later damage due to the moisture-related shrinkage or swelling. Many building moisture meters with a choice of material offer characteristic curves for different types of wood.

With building materials that are processed while moist, such as in-situ concrete, screed, plaster and paint, some of the moisture is gradually released into the environment during the setting and drying process. If a covering or coating is applied to these materials before the permissible residual moisture level is reached, which prevents the moisture from being released into the environment, this layer will most likely be damaged. Therefore, tilers, floor layers, painters and carpenters are obliged to check whether the subsoil and the environmental conditions on the construction site are suitable for the service they are to provide. The electronic building moisture meter is ideal for builders, craftsmen and architects who want to check the moisture content of the substrate without damaging it.

Applications for building moisture meters at the stage of use of the buildings
During the usage phase of the buildings, there can be increased humidity in some parts of the building due to more or less direct water impact, for example due to penetrating precipitation, burst pipes, defective washing machines or dishwashers, leaking water or sewage pipes or spray water from bathing and showering areas. On the other hand, moisture damage can also occur as a result of the increased humidity over longer periods of time. As a rule, these first occur at typical geometric or material-related thermal bridges, where condensation forms due to the lower temperatures. If the cause of the damage is not clearly recognizable, the building moisture meter can be used to quickly narrow down which areas have increased moisture values and how the values are distributed in this area. Conclusions can often be drawn from this as to the cause of moisture and suitable measures for elimination or for further investigations can be initiated.

Many building materials release the moisture absorbed in the event of the water damage only slowly to the ambient air via evaporation. So that the affected rooms can be prepared and used again more quickly, the drying process in the event of major water damage in the buildings is often accelerated by additional heating and/or dehumidification of the room air. The success of the drying measures can be checked regularly with the building moisture meter so that they are not ended too early, but also not continued for an unnecessarily long time.

Whether to check the moisture content of wood products, to determine the residual moisture in a screed or to quickly determine the surface spread of water damage – many electronic building moisture meters are basically suitable for these measuring tasks. The large number of available models differs, among other things, in the measuring principle and its implementation, in the type of sensors or electrodes, in the range of material-specific characteristics and in additional functions and measured variables.

Measuring principle
The measuring principle and its implementation determine, among other things, the measuring depth and the susceptibility of the measurement to failure. With the building moisture meter that measures electrical capacity, the device is placed on the surface and, depending on the composition of the material, measures up to a depth of about 5 cm. Building moisture meters, which determine the moisture content of a building material via electrical conductivity or electrical resistance, have sensors that are inserted into the material or drilled. For many models there are electrodes in different lengths and designs that are interchangeable. Long electrodes, where only the tip is conductive, enable targeted measurements at different depths. This makes it possible to make statements about the moisture distribution in the component cross-section. Also, the building moisture meter that measures capacitively via a permanently installed probe can also offer the possibility of measuring in deeper layers with additional electrodes using the resistance method.

Selectable material characteristics
Many building moisture meters offer the option of selecting stored material characteristics for wood or building materials. The measured values then displayed enable a direct comparison with reference values for the equilibrium moisture content that usually occurs in this material. With the values determined in this way – just as with those with a material-independent scale – it should be noted that building constructions and building materials are often not homogeneous. However, the plausibility of the values can easily be checked by means of the control measurements in the vicinity of the examined location. With the resistance method, the measured values also depend on the temperature. If the building moisture meter does not have temperature compensation, the temperature influence must also be taken into account by the user.

Additional functions and additional measured variables
Some structural moisture meters offer a graphical dial display, a dry/damp/wet rating, or preset or even adjustable alarms. This makes routine checks on similar building materials much easier, for example when delivering wood or chipboard to the construction site or workshop. There are also device models in which the measured values can also be saved. With some newer types, the measurement data is transmitted to a mobile device via Bluetooth and can not only be read there in the associated app, but also saved or sent.

The air temperature and the relative humidity are available as additional parameters for the building moisture meter. On the one hand, these values can be used to assess whether the measured material moisture content is normal or too high under these environmental conditions. On the other hand, direct conclusions can be drawn from the measured values as to whether the building materials at thermal bridges are endangered by condensation.