The waterproofing of below ground structures through careful design, the right choice of waterproofing materials and professional workmanship is absolutely critical when you consider that 75% of building failures can be attributed to water ingress.

While British Standard BS 8102:2022 considers three forms of construction and structural waterproofing protection, specifiers have traditionally chosen one solution over another for a new build application. But with water ingress having such financial implications, there is now a growing trend to incorporate multiple systems, particularly a dual system approach of watertight concrete and a membrane system to provide two layers of protection.

Every building or structure needs waterproofing which in the long-term is the most cost-effective way to maintain its value. Defects can occur in any waterproofing system, but the risk can be minimised through design, planning and a waterproofing specialist who can offer expert specification advice and a high level of site support during construction.

For the specifier, BS 8102:2022 gives recommendations on three different waterproofing methods, Type A, B and C, the choice of which should take into consideration all of the relevant project requirements. The three types of waterproofing are:

  • External or internal ‘tanking’ (Type A) typically using a membrane such as SikaProof, SikaPlan, Sikalastic, Mortars and bitumen coatings
  • Cementitious render system (Type A) – Sika 1-Pre bagged
  • Integral protection (Type B) using an appropriate concrete mix design and admixtures providing a watertight barrier – Watertight concrete
  • An internal drainage membrane (or water management), (Type C) that collects and disposes of water that enters the structure – Sika Cavity Drainage

Although each system has its own advantages and suitability for specific projects and applications, most manufacturers only offer one type, so are only able to ‘recommend’ their system. However, with projects becoming increasingly complex, specifiers are moving to a more integrated approach, one where different solutions are combined and used to their strengths, to create a highly robust waterproofing strategy.

As the UK’s only manufacturer to provide a complete range of structural waterproofing systems, including tanking membrane, cementitious render, watertight concrete and cavity drain, Sika is ideally placed to provide the impartial advice on the creation of the optimum waterproofing strategy.

Waterproof Future Proofing

To ensure buildings remain impenetrable to water whilst meeting the building standards of today and the future, a measured and evaluative approach to the selection of a product needs to be taken. A single solution may not be the right approach. The NHBC, along with other insurers, has also upped the ante having raised standards of waterproofing most notably in terms of habitable below ground accommodation, insisting that a combined approach to waterproofing should be used for Grade 3 environments.

As the all-round solutions provider, Sika is able to consider the entire waterproofing process. Through specification advice and guidance, as well as detailed assessment of a project and on-site support, Sika ensures waterproofing solutions are designed, delivered and maintained in line with BS 8102:2022 recommendations.

Advantages of using the Sika Dual Waterproofing System:

  • 20-year guarantee
  • Two lines of defense
  • Compatible Systems
  • Engineered Solutions
  • Single company providing support and guaranteee
  • On-site inspection and support