Wayne Chissel of WestWood Liquid Technologies, discusses the urgent need to improve roofing standards in the housing sector and the role of PMMA liquid waterproofing systems
In the ever-evolving landscape of social housing, there is not only a pressing need for greater compliance but excellence in roofing and waterproofing standards. When refurbishing homes, durability and safety in social housing should not be left to chance. Manufacturers appointed for these upgrades must be accountable and work with housing providers and specifiers to deliver products that exceed minimum requirements.
The Power of PMMA
When refurbishing a roof, Polymethyl Methacrylate (PMMA) liquid-applied waterproofing systems play a key role in raising both safety and quality standards. Although PMMA is not a new or emerging chemistry, it has significantly evolved. Thanks to ongoing research and development, PMMA provides a highly versatile and robust waterproofing system which can be used for various applications across the housing sector including flat roofs, balconies, walkways and car parking.
PMMA-based systems, which are solvent free and cold applied, tend to have a minimum of two components – the resin and a catalyst or activator. Contractors will mix the components together on site, starting an exothermic reaction to initiate the curing process.
A polyester reinforcing fleece, which is first saturated within the waterproofing layer, bonds the membrane to the substrate as it is applied in its wet state. The surface layer is then installed onto the embedment coat while still wet to form a single, seamless membrane of uniform thickness.
Safety First
A key advantage of using a PMMA system is that it does not require an open flame to install on site, which is a huge health and safety benefit for the contractor, client and end user. To date, there have not been any incidents of fire recorded globally on a roof due to PMMA being installed.
As with any construction site work, there are always risks associated with building. At WestWood, our protocol is not to sell products to any contractor that hasn’t undertaken our mandatory contractor training. This is paramount to ensure the safe installation of our PMMA systems and guarantee a robust solution for the customer.
Minimising Disruption
Another reason why PMMA is so successful is that it can rapidly cure, making it ideal for occupied housing blocks. The liquid membrane can be cured in as little as 15 to 20 minutes even at sub-zero temperatures. With variable amounts of catalyst added to the resin, the curing times can be controlled on site to suit the requirements of the installation team.
Certain PMMA systems can also be applied in temperatures as low as -15°C. This means projects can be completed in all weathers, reducing the risk of delays and further minimising disruption for residents.
As a long-term solution, PMMA provides peace of mind too. With durable, flexible and hard-wearing properties, PMMA ensures watertightness for up to 25 years. Third-party accreditations such as BBA, ETA, and FM Approval provide further assurance the roof will meet building regulations and perform as expected.
Setting the Standard
From a manufacturer’s perspective, embracing standards like BROOF(T4), ensures more accountability and quality assurance.
BROOF(T4) classification, obtained through TS 1187 within the EN 13501-5 standard, evaluates roofing materials’ fire performance. It specifically measures their resistance to external fire exposure, which is crucial for preventing flame penetration and spread. BROOF(T4) compliance is integral, ensuring roofs meet stringent fire safety standards and bolsters occupants’ safety by reducing the risk of flame spread.
This regulation significantly influences specification, necessitating high fire-resistance materials. Commonly used system build-ups meeting BROOF(T4) include PMMA liquid-applied membranes.
During installation of a liquid-applied membrane, manufacturer training and guidelines must be adhered to, which includes robust sealing, appropriate detailing at roof penetrations, and integration with other fire safety measures like compartmentation and fire barriers.
By seeking relevant training and certifications to demonstrate competence in designing, installing, and maintaining fire-compliant roofing systems, roofing professionals can achieve regulatory compliance while enhancing the roofing industry’s reputation and buildings’ fire safety.
Partnership working
Raising standards in housing refurbishment can’t be achieved through products alone. With residents often remaining in-situ during refurbishment, meticulous planning, seamless coordination, efficient execution and quick application are all paramount. Collaboration is key in this respect requiring manufacturers, contractors and the client to work together to achieve the best possible outcome.
Through effective partnership working and products which go beyond minimum requirements, project teams can navigate challenges effectively while upholding the highest standards of safety and quality.
Wayne Chissell is technical director at WestWood Liquid Technologies