TECHNICAL INSIGHT: ROOFING
LIQUID ROOFING DELIVERS SPEED, SAFETY AND PERFORMANCE Liquid applied waterproofing is becoming an increasingly popular flat-roofing solution for building owners, designers and contractors offering, as it does, a wide choice of highperformance system solutions for a host of requirements and applications. Suitable for roofing refurbishment, repair, new build, complex and inverted roofs; new formulations have enhanced its appeal over alternative bonded or torch-on systems, says Simon Ashworth, Product Manager – Liquids & Synthetics at BMI UK & Ireland. BMI UK & IRELAND
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n refurbishment, liquid applied waterproofing could be considered to deliver ‘renewability’ benefits, with its capacity to be applied over existing roofs – whether cement, metal or single-ply. This ability to overlay also makes it ideal for repairs. In both situations, the fact that it fully bonds to a variety of substrates makes it a versatile, reliable problem solver, particularly when restricted threshold heights, programme time and building occupancy are key considerations in the system specification process. For new builds or where the roof features a large element of detailing – outfalls, penetrations, upstands and the like – liquid applied waterproofing delivers the flexibility to provide fast, accurate and secure finishes. Where access is an issue, it can easily be laid without power, where lifting to the FC&A – JULY – 2020
roof is difficult or where storage of bulk materials would be challenging. Finally, it is ideal for inverted roofs – such as green or blue roofs – where waterproofing reliability is a concern as failures would be particularly challenging to remedy.
Such a superior protective, waterproofing characteristic is a function of seamless fabric reinforcement, combined with high-performance polymers – either polyurethane (PUR), Modified Polyurethane or Polymethyl Methacrylate
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(PMMA). The result is a durable, joint-free, monolithic membrane system that maintains its integrity in the face of temperature-driven expansion and contraction. It’s this seamlessness that also makes it ideal for complex detailing, providing a homogenous seal around edges, rainwater outlets, terminations and HVAC units. Chief among recent innovations is the introduction of new, proprietary solventand VOC-free materials. Being low odour and 100% hazard-free, these products – such as BMI UK & Ireland’s Sealoflex Ultima – are a superb choice in refurbishment applications where there may be environmental sensitivities – such as concerns around the impact of odour and vapour on contractors, building occupants or the public at large.
