Workmen in a basement

What is combination waterproofing?

21 October 2018

At Timberwise we have 50 years of experience in providing interior and external waterproofing solutions throughout the UK. We design and implement waterproofing systems in line with guidelines set out in BS 8102 2009, according to these guidelines Waterproofing Design Specialists should consider using more than one type of waterproofing to provide enhanced protection from water ingress.

The types of waterproofing available

Timberwise provides waterproofing products for all three types of waterproofing, defined within BS 8102:2009 as:

Type A: Barrier Protection (External, Sandwiched or Internal)

Type B: Structurally Integral Protection (Usually to the relevant British Standard and of reinforced concrete structure) (BS 8007 and BS 8110)

Type C: Drained Protection (Cavity Drain Membranes and Construction Drained Cavities)

Type C

When is the right time to recommend a combination waterproofing solution?

Waterproofing Design Specialists take into consideration combination waterproofing in particular when:

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

What combinations of waterproofing are available?

Type A, B & C        Type A & B               Type A & C          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.

Combination waterproofing design & installation

As recommended by the “BS 8102:2009 – Code of Practice for Protection of Below Ground Structures Against Water From The Ground’ the inclusion of a Waterproofing Design Specialist is essential to design an integrated waterproofing solution.

Timberwise can take full responsibility for the design and liability for the basement waterproofing design in your building project and our systems also meet the guidance set out by in NHBC chapter 5.4 and Local Authority Building Control (LABC) guidelines.

Contact a Waterproofing Specialist

In need of expert waterproofing advice?