What are examples of moisture

The expression humidity indicates the presence of water in a substance or a gas.

If the moisture is on the surface of a substance, one speaks of moisture, condensate, or adsorption.

Gaseous moisture is generally referred to as air humidity and in combination with liquid water as mist, fog or wet steam. The moisture in the soil is referred to as soil moisture, that of the skin as skin moisture and that of the wood as wood moisture.

The moisture of a substance is linked to many different properties. Examples of this are the swelling resistance, the electrical conductivity, the thermal conductivity, the coefficient of friction and the drying properties.

The removal of water from a surface or from a substance is generally referred to as drying or drainage.

Humidity in buildings

In buildings, moisture can accumulate in different places and for different reasons and lead to harmful mold formation in the masonry.

External causes

  • Rain and thawing snow can penetrate through leaky roof coverings.
  • Water that penetrates into the basement walls laterally in the ground (so-called stratified water) can, often a problem in buildings on slopes, penetrate the masonry after heavy rainfall.
  • Groundwater that reaches as far as the basement (so-called pressing water) is another source of damp walls. If the building is not properly sealed, it can rise against gravity in the walls due to the capillary effect of the building material used.

Countermeasures exist in all of these cases in the professional waterproofing of the corresponding parts of the building.

Internal causes

Sources of moisture in buildings are, for example, showering, cooking, washing, drying laundry and ironing. During these processes, the humidity is increased. The water vapor stored in this way is deposited in colder places in the building, such as on window panes, outside walls, edges and corners as well as thermal bridges on roller shutter boxes above windows.

This condensation moisture and the warm indoor air offer the best living conditions for molds, the spores of which can cause health problems such as allergic reactions.

Preventive measures are regular ventilation and an adapted living climate with a relative humidity between 45 and 50%. In winter, when the less well-thermally insulated outer walls get particularly cold, short-term so-called burst ventilation with the window fully open several times a day is recommended to save heating energy.

Another, much rarer source of moisture in buildings is a leak in the water piping or a water pipe burst.

See also

Categories: Thermodynamics | Materials science