Generally, building foundations are made of concrete which is a porous and hygroscopic material. In case of constant impact of excessive humidity, this leads to rapid wear of structures, appearance of mould, cracking of foundation, misalignment and warping of the walls.
In places where precipitation is rare and scanty, or where underground waters are far from the surface, waterproofing might not be necessary. In other cases such protection is required for foundations of any type, regardless of availability or absence of basement premises.
Waterproofing is necessary to achieve the following aims:
reinforcement of structures and enhancement of their durability;
prevention of misalignment and warping of the bearing walls and foundation;
prevention of cracking, appearance of mould and rot;
protection against flooding of basement premises;
facilitation of the building foundation maintenance;
protection against the harmful effect of precipitation and wind.
In ancient times the builders performed waterproofing using tar, wax and special mastic compounds which were applied to wooden elements of foundations. Nowadays there exist modern methods of protection of foundations against water. It can be a penetrating technique that makes use of compounds which penetrate deep into the material, a coating (pargetting) technique which involves application of multilayer coating containing bituminous, resinous or other compounds, or the recently developed injection waterproofing technique that involves pumping of polyurethane, epoxy, acrylate gels or polymer-cement suspensions into the foundation.