The Types of Waterproofing
The British Standard for Waterproofing, BS8102:2009 defines 3 “Types” of waterproofing.
Understanding the properties and the requirements of each type is crucial for the success of any basement waterproofing project.
Type A Waterproofing
Type A Basement Waterproofing Systems are barriers that are applied to the structure. And can be used either externally or internally.
- Type A Waterproofing Barriers can be external:
Pre-applied systems such as Delta DualProof are ideal for new concrete structures. The integral polyprop fleece bonds to the outside of the new concrete creating a watertight seal.
Post-applied Type A waterproofing systems such as Koster Deuxan 2c work really well to seal the outside of ICF or blockwork retaining walls
- Type A waterproofing can also be used internally:
This is often used on the refurbishment of existing structures. Koster NB1 Grey fully is used to waterproof masonry walls, basement soffits and concrete slabs.
Type B Waterproofing
Type B Waterproofing is waterproof concrete or watertight concrete. Although an additive system can be used to provide a waterproof concrete structure. 300mm Concrete walls and slabs formed to BS EN 1992 with a maximum crack width of 0.2 can be considered waterproof. We would recommend the use of Koster Quellband to seal the below ground construction joints. This is a swelling hydrophilic waterbar that is included in the construction joint.
Type C Waterproofing
Type C Waterproofing is cavity drainage. Here a sealed drainage system is used internally to divert any water that enters through the basement slab of the walls into a drainage system such as a groundwater pump or, if the topography of the site allows, out to an open aspect.