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NHBC Chapter 5.4 – ‘Waterproofing of Basements and Other Below Ground Structures’
The National House Building Council (NHBC) clarified the recommendations of BS 8102:2009 with the introduction of Chapter 5.4 – ‘Waterproofing of Basements and Other Below Ground Structures’. The new Chapter introduced significant positive changes in how the house-building industry considers below ground waterproofing – including the upskilling of designers and installers, and changes to future designs.
Key recommendations include:
Design and Construction Requirements
Chapter 5.4 explains where waterproofing may be required, and where its recommendations apply. Structures requiring waterproofing range from those where the external ground levels have been raised to within 150mm of the internal floor finish, to deep basements that are several levels below ground, and include all structures near to or below ground level where waterproofing may be required.
Defining Structures That Require Waterproofing
The Chapter explains that the range of structures that require waterproofing goes significantly beyond what readers might typically consider as ‘basements’. Below ground constructions that generally require waterproofing, and should take account of the new Chapter, include:
Near-to-ground constructions that may require waterproofing also include:
Robust design should be undertaken by suitably qualified waterproofing experts, and be suitable for the specific ground and building conditions. The design should:
Only systems, including important ancillary components, which have been assessed and proven to provide suitable performance in a given situation should be used. Waterproofing should:
Recognising the importance of ensuring correct installation in accordance with the manufacturer’s recommendations, waterproofing should only be undertaken:
Reduced Risk, Reduced Cost
By following the guidance and meeting the performance standards, the NHBC are confident that construction quality and robustness of below ground waterproofing will improve significantly, resulting in reduced need for remedial works, cost and disturbance for homeowners.
NHBC Advise That You:
How We Can Help
Newton Waterproofing Systems support all the guidance provided by the NHBC in the Chapter. We recommend a Newton Specialist Basement Contractor (NSBC) is involved in a project where a new-build or existing basement needs to be waterproofed. NSBCs work in partnership with Newton and can take responsibility for both the design and the installation of a waterproofing system, which means that they will give meaningful, insured installation guarantees for the work that they undertake.
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.