Without adequate protection, hazardous gases can advance into buildings from the ground, jeopardising the health of inhabitants, damaging the building and risking non-compliance with Building Regulations. Therefore, it is vital to choose the correct ground gas management solution to maintain safety and compliance.
NHBC Guidance
The National Housebuilding Council (NHBC) Foundation produces guidance ensuring that new housing is constructed safely and meets performance requirements. In 2023, the NHBC published NF94 Hazardous Ground Gas – an essential guide for housebuilders; the latest update to the area which supersedes previous guidance.
The new document advises against the use of gas protection membranes containing foil linings for ground gas management on NHBC-registered housing developments, instead recommending non-foil alternatives.
According to the NHBC, aluminium foil can be vulnerable to corrosion when in direct contact with concrete, which can compromise the long-term durability and effectiveness of the gas barrier. Conversely, non-foil gas barriers can offer long-term, compliant ground gas management solutions.
Compliance and Performance
In response to the new guidance, Visqueen has released a range of non-foil gas barriers which meet NHBC NF94 recommendations. Visqueen’s new high-performance NF range offers solutions for Type A, B and C locations in NHBC-registered housing.
The range comprises of Visqueen’s Gas Barrier NF-400, Ultimate Gas Barrier NF-500, and Ultimate Gas Barrier NF-600 membranes. Encon & Nevill Long branches also offer a fully compatible range of Visqueen non-foil system accessories, including tape components and the Visqueen NF-Detailing Strip, ensuring a fully compliant system approach.
Visqueen Gas Barrier NF-400 is suitable to prevent the ingress of harmful levels of methane, carbon dioxide, radon and moisture into all building types. The NF-400 membrane is suitable for Type A locations where membranes are installed above the structural floor slab under NHBC Guidance. In addition, it meets requirements under BS 8485:2015 + A1:2019, the code of practice for the design of protective measures for methane and carbon dioxide gases in new buildings. This British Standard makes no distinction regarding membrane placement, permitting installation either below or above the structural floor slab in accordance with site requirements.
Visqueen Ultimate Gas Barrier NF-500 and NF-600 offer resistance against volatile organic compounds (VOCs) in both vapour and liquid form, in addition to ground gases. The NF-500 membrane is suitable for Type A and Type B locations, either below or above the structural floor slab.
Finally, Visqueen Ultimate Gas Barrier NF-600 is appropriate for more complex designs in Type A, B or C locations; offering a comprehensive solution to the highest ground gas or VOC exposure levels.
Practical Solutions
All three gas barriers feature a transparent, tinted finish to enhance visibility of the substrate during and after installation. This ensures both the installation and verification processes are as straightforward as possible, providing peace of mind for housebuilders.
The Distributor of Choice
Visqueen’s NF Gas Barrier range is available nationwide from Encon & Nevill Long branches, including all system elements. We support housebuilding projects across a range of solutions, offering reliable deliveries direct to site or for collection when they need it, including full plot loads.
Through our trusting relationships with leading manufacturers such as Visqueen, Encon customers can also access technical support through the manufacturer’s expert technical teams to ensure applications meet performance requirements and regulations.
To find out how we can support your next housebuilding project, email support@encon.co.uk, or find your local branch to discuss your requirements with our experienced teams.
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