What Is the Difference Between Damp-Proofing and Waterproofing?

The selection of hydro-insulation depends on the soil conditions and the groundwater level at the construction site. Damp-proofing and waterproofing serve different purposes, and conducting a soil survey should be the first step before starting construction. This will help determine the right type of hydro-insulation for the project.

Damp-Proofing vs. Waterproofing

• Damp-proofing protects against non-pressurized water, such as rainwater and capillary moisture from the ground.
• Waterproofing shields foundations from pressurized water that exerts force on the underground parts of the building, providing a higher level of protection.

It is not always possible to predict future threats to a building’s foundation. Even newly built houses in the surrounding area can alter the groundwater level, increasing the risk of water pressure on foundations. If pressurized water appears, damp-proofing alone will not be sufficient.

Damp-Proofing (Moisture Barrier)

• Applied to the subterranean and base levels of a building situated above the groundwater table.
• Used when there is no hydrostatic pressure from rainwater on foundations or foundation walls.

Waterproofing

• Applied to the subterranean and base levels of a building located above the groundwater table, but in impermeable soils where hydrostatic pressure from rainwater is present.
• Required when the building’s foundation (or parts of it) are positioned below the groundwater table.

Definitions according to Maciej Rokiel, Renovation of Building Structures, in "Izolacje" 1/2019.