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Three Types of Waterproofing

Newton provide waterproofing products for all three types of waterproofing, defined within BS 8102:2009 as:

Type A – Barrier Protection

Type AThe 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.

Type B – Integral Protection

Type BThe structure itself is constructed to be integrally waterproof and the primary resistance against water ingress.

Type C – Drained Protection

Type CIf water passes through the structure, it is depressurised and collected by the internal Cavity Drain System and then safely removed from the building.

When Should A Combination Waterproofing System Be Specified?

Waterproofing Design Specialists are tasked to recommend a “combined“ waterproofing system approach particularly where:

  • The likelihood of leakage is high.
  • The consequences of leakage are unacceptable.
  • Additional vapour checks are necessary for a system where unacceptable water vapour transmission could otherwise occur.

With this in mind, the possible combinations of waterproofing are:

  • Type A, B & C
  • Type A & B
  • Type A & C or
  • Type B & C

Usually a combination of 2 forms of waterproofing is adequate when designing a habitable space requiring a completely dry internal environment, defined as ‘Grade 3’ within BS 8102:2009.

Whichever combination of waterproofing is chosen to achieve the Grade 3 environment, in most cases the safest combination will include a ‘Type C’ internal cavity drain membrane system as one of the forms of waterproofing. The choice of the other system is largely dictated by the type of structure.

quotation marks“I have twenty years experience dealing with problems of moisture in buildings and have found Newton Waterproofing to be top of the tree when it comes to products, experience and technical understanding of structural waterproofing design and installation. The public and professionals alike can approach Newton’s with confidence.”James Hockey, Director – Trace Basements.


Example of a Typical Combination Waterproofing Design

Waterproofing Design

A typical combination waterproofing design showing Newton CDM Cavity Drain System internally (Type C), Newton HydroBond System externally (Type A), and Newton HydroTank System with waterbars and waterstops within the structure itself (Type B)


Newton highly recommend that installation is undertaken by a Newton Specialist Basement Contractor (NSBC).

NSBCs can provide a meaningful insured guarantee and take full design liability on the project, fulfilling the role of ‘Waterproofing Specialist’ as recommended by the BS 8102:2009 ‘Code of Practice for Protection of Below Ground Structures Against Water From The Ground’. Please contact us for a list of NSBCs in your area.

Speak to our friendly, expert team

Our staff are able to provide guidance for projects of all sizes, whether you require some general advice about damp or waterproofing, or support with technical drawings and specifications.

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