ROOFING & CLADDING
LIGHTS, CAMERA, ACTION FOR BFI SOUTHBANK ROOF REFURBISHMENT The BFI Southbank sits directly underneath Waterloo Bridge; a Grade II* listed heritage structure, but extends to both sides, where roof areas totalling 350m² were in need of refurbishment. The roof areas are composed of 38 raised GRP decks with a rooflight in each section and an expansion joint between sections, with vented vertical surfaces and metal decked gulleys that also needed refurbishment. The ARBOFLEX® PU cold-applied liquid waterproofing membrane from CARLISLE® was chosen, installed by Martins Roofing Contractors Limited. Each GRP roof section has raised channels a few millimetres high running from side to side across the thin strip of roof. Because of these undulations, it was not possible to include the matting usually installed as part of the ARBOFLEX PU system in the specification. Instead, two additional coats of liquid waterproofing were applied and allowed to cure prior to application of the next, forming a robust waterproofing layer. The U/V top coat was then applied to the cured surface to provide a fullywarrantied 20 year system.
solution “ The allowed us to
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For the vented vertical sections, the ARBOFLEX PU system was applied with the correct ratio of thickener, providing suitable viscosity and adhesion to enable the cold-applied liquid membrane to be used to waterproof these roof areas and provide consistency across all aspects of the GRP roof. The expansion joints between the GRP roof sections needed to be stripped and replaced and Arbomeric MP20 sealant from ARBO, part of CARLISLE, was specified for these joints. The sealant was installed at each expansion joint and colour matched to the grey ARBOFLEX PU, with a conventional installation of the cold-applied liquid waterproofing, matting and U/V top coat applied onto the cured sealant.
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carry on with our normal operations below with very limited disruption and gives us confidence in the roof again, which is especially important as we have public space and exhibitions below.
Installation of the waterproofing system had to be co-ordinated with replacement of the rooflight units, and a cure accelerator was added to the ARBOFLEX PU liquid system for the sections around the rooflight apertures so that each new unit could be fitted within an hour of the waterproofing being completed.
The profiled metal deck gulleys were stripped back, cleaned and primed, with a vapour control layer laid onto the prepared deck, followed by a fullyadhered, non-combustible mineral wood insulation. A further application of primer and a carrier membrane were then installed, followed by the liquid waterproofing system. Duncan McKeich, head of facilities at the BFI commented: “The solution allowed us to carry on with our normal operations below with very limited disruption and gives us confidence in the roof again, which is especially important as we have public space and exhibitions below.” Website: www.ccm-europe.com/gb