A new construction industry initiative is hoping to raise standards in basement construction and reduce the incidence of leaks and faults.
The National House-Building Council (NHBC), the leading insurance and warranty provider for new homes in the UK, last year reported that claims on basements since 2005 have cost the industry a total of nearly £21m – affecting 890 homes. (See previous report here.)
NHBC has been working across the sector with the aim of forming a cross-industry committee to focus on the key issues affecting basements in the UK and help shape a new set of standards.
Since the publication of its report last year, the NHBC has met with builders, manufacturers and suppliers to discuss issues such as improved design and installation standards, improved training and the formation of a new cross-representative committee. It hopes that the new committee, once established, will be able to lobby parliament on planning and regulation issues relating to the industry.
The Basement Information Centre and the Property Care Association are among the groups with which NHBC has already met in an attempt to address basement problems.
Following further cross-industry discussions and new surveys of live sites, NHBC plans to issue a new Standards chapter that will build on the current benchmark standards and offer practical guidance for structural waterproofing and the construction of basements. This will be included in the NHBC Standards 2015 edition to be published later this year.
NHBC technical projects manager Marc Separovic said: “Meeting with so many organisations, companies and individuals within the industry has enabled us to gain a detailed understanding of good practice on numerous aspects of basement construction including waterproofing systems.
“The benefits of working together are established and ultimately with the introduction of the new basement chapter, will raise standards and begin to reduce the number of costly repairs as a result of defective basement construction.”
NHBC’s initial report into basement problems found that nearly all basement claims were a result of water ingress, not structurally related, and that the majority of large claims from 2012 were due to workmanship and design failures associated with externally tanked Type A systems.
The report also highlighted a lack of adequate ground investigations being carried out to establish the existing ground water conditions and ensure the correct waterproofing system is used.