A large number of structural waterproofing projects have been completed by ourselves, ranging from small domestic cellars to large commercial basements.
We often work closely with the client or Architect at the design stage as projects will require waterproofing to comply with BS8102: 2009 The Code of Practice for ‘The Protection of Below Ground Structures against Water from the Ground’.
All of our Surveyors are qualified to CSSW standard and are able to provide detailed designs for any required below ground waterproofing project, using the systems which they feel will be the most suitable, trouble free and effective. There are a variety of waterproofing systems available and BS8102: 2009 The Code of Practice for ‘The Protection of Below Ground Structures against Water from the Ground’ suggests that waterproofing designers consider a combination of waterproofing systems for retained structures where the likelihood of leakages is high or the consequence of leaks is unacceptable.
There are three types of waterproofing defined by BS8102: 2009 The Code of Practice for ‘The Protection of Below Ground Structures against Water from the Ground’:
Barrier Protection (Type A)
The structure has no integral protection against water and relies on a membrane to be introduced internally or externally to prevent the ingress of water into the inner building fabric. Examples of barrier membranes applied externally to the ‘positive’ side are bonded sheet membranes, sodium bentonite matting, liquid applied coatings (cementitious/bitumen or polymer).
Internally similar approaches can be adopted to hold water back on the ‘negative’ side of the below ground structure such as cementitious coatings, bitumen or polymer based liquids applied via spray, trowel, brush or roller.
Integral Protection (Type B)
The structure itself is constructed to be integrally waterproof and the primary resistance against water ingress. These types of structures will be of high grade concrete, usually with more reinforcement fabric introduced to reduce risk of shrinkage cracks and, as such, water ingress.
In addition, these forms of structure will have waterbars (hydrophilic) which swell on contact with water, to protect the vulnerable construction joints from the risk of water penetration, or injection waterbars that have the capability to inject grout to porous and poorly compacted joints as well as resins for post construction leak sealing.
Drained Protection (Type C)
It is accepted that water could enter the building and an internal cavity is provided to depressurise and manage the water. Type C systems include HDPE dimpled sheets with maintainable internal drainage to guide water via gravity to open elevations or to be removed by mechanical means.
Usually on new build projects a combination of two forms of waterproofing is adequate when designing a habitable space that requires a completely dry internal environment defined as Grade 3 within BS8102: 2009 The Code of Practice for ‘The Protection of Below Ground Structures against Water from the Ground’.
Our waterproofing systems are designed for internal and external waterproofing of new builds and refurbishment projects and include cementitious (Type A) and Cavity Drain Membrane (Type C). We are also able to offer full sump pump installations and the industry accepted 10 year term guarantee. An optional underwritten insured guarantee is also available.