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 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 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 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.