Built-up roofing systems have enjoyed a major market share for many years. They have attained this position through continued excellence of performance, and through versatility in design, however in the past decade they have faced fierce competition from alternative methods of construction; systems and products that were deemed to offer savings both in terms of cost and time. The landscape in 2021 looks different, the industry has been forced to change its mindset and for good reason. Rather than focus on cost and time being the main drivers behind a roofing specification, these decisions are becoming increasingly guided by wider socio-economic issues, as well as compliance with the latest building regulations.
Brexit and COVID – a double whammy for supply chains
During the first lockdown in 2020, contractors and construction product manufacturers were buoyed by the government’s renewed commitment to ‘build back better’ through a new deal that promised a major reform to the planning process. That reform manifested itself as ‘The Business and Planning Bill’, effectively allowing land owners to seek permission for longer working hours on site, the idea behind this was to combat the delays associated with social distancing on site. And it worked – factories re-opened their doors, builders and engineers went back to site and it wasn’t long before demand for labour and materials returned to pre-lockdown levels. Why is this relevant? In short, the supply of construction materials relies on three key factors: production, delivery and stocks. All were significantly disrupted by the pandemic, but the speed and scale of this recovery in some sectors was completely unprecedented. Production, delivery and stocks struggled to keep pace with demand, lead times increased tenfold and certain materials became almost impossible to source, particularly materials imported from abroad. Pressures on supply chains were quickly apparent through price increases, in some cases as much as 30% for raw materials and so with Brexit on the horizon and the threat of import tariffs adding to already inflated material costs, stockpiling became a priority for suppliers and manufacturers. Almost by accident, this created a need for additional storage facilities and warehousing for stockpiling raw materials – warehouses that needed safe and secure twin skin roofing to ensure the protection of the high-value goods housed within them.
Flexibility & Performance
With global supply chains faltering, twin-skin roofing offers a reliable solution with UK manufacturing roots. The nature of a built-up system allows more flexibility at procurement stage when compared with composites; linings, insulation, top sheets and in some cases standing seam roofing systems are typically interchangeable, with many system manufacturers offering tested and warranted solutions incorporating a multitude of different materials from different manufacturers. Mineral wool insulation and coated steel sheets are manufactured in significant quantities within UK based factories, reducing pressure on international supply chains and alleviating the associated extended lead times. In wider terms, this method of construction affords the specifier more opportunity to influence the performance characteristics of the roof structure, for example by varying the insulation thickness to improve thermal performance, or by introducing a perforated acoustic liner sheet to absorb and control sound in certain environments.
Compliance has become a watch-word for our industry, so it would be remiss not to mention fire performance; twin-skin roof systems often incorporate Class A1 rated mineral wool insulation; thus, it is possible to construct a roof with a fire resistance rating of up to 4 hours, the same is applicable to walls built using this method. When comparing this with composite panel alternatives, the difference is stark, composite roof sheets are typically manufactured with a phenolic insulation core which achieves Class D or ‘medium contribution to fire’. In safety terms, it’s an obvious choice.
Social & Environmental Impact
Our internal environment has never been under more scrutiny than during the pandemic, with the need for well-ventilated and healthy environments being paramount for businesses and institutions. The breathability associated with twin-skin roofing systems means that air circulation is more easily achieved than with composite or liquid roofing systems, of course it doesn’t have the same effect as opening a window or a door, but will certainly contribute to a healthier indoor environment for occupants as we navigate our way through unchartered territory. Furthermore, we can lessen our environmental impact by using materials and systems that are readily recyclable. Individual system components, like bars, brackets and sheets are much easier and cheaper to recycle than bonded panels that use a lot of adhesive and toxic chemicals in their composition – better for the environment and better for our communities.
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