Basic concept of capillary dampness

Capillary dampness is a phenomenon that occurs when water rises naturally from the ground towards the structures of a building through the pores and capillaries of the construction materials. This process occurs mainly in walls, foundations and foundations that are in direct contact with humid soils or with a high presence of groundwater.

This type of humidity is one of the most common causes of deterioration in buildings, since rising water causes damage to materials, encourages the appearance of salts and affects both the functionality and aesthetics of buildings. Capillarity is a physical phenomenon that is based on the adhesion and cohesion of water in narrow spaces, which allows its rise against gravity.

Ground conditions and water table

The main origin of capillary damp lies in the presence of moisture in the soil, especially when the water table is high. This means that the groundwater is very close to the surface, favoring its rise towards the construction elements in direct contact with the ground.

Soils with a high water retention capacity, such as clay soils, intensify the phenomenon due to their fine structure that facilitates the absorption and transport of water by capillarity. Furthermore, poorly drained land or areas with deficiencies in the evacuation of rainwater increase subsoil humidity and, therefore, the risk of capillary rise.

The design and execution of foundations without adequate barriers or effective waterproofing also contributes to water penetrating and rising, aggravating the problem in the built structure.

Characteristics of construction materials

Porous materials such as masonry, brick, concrete and mortar have numerous capillaries that act as channels for the rise of moisture. The permeability and porosity of these materials determine the speed and amount of water they can absorb and transport to higher areas.