Non-fragile roof assemblies pass the test of time

Liam Burgess, Head of QSHE for CA Group, discusses roof safety when accessing and maintaining solar photovoltaic installations. 

As more and more roofs are being used for rooftop solar photovoltaic (PV) arrays, the ability to safely access and maintain these installations is becoming increasingly important. The subject of working at height and the non-fragility of roofing systems is therefore hugely important when considering newbuild and refurbishment roof systems.  

Unlike many alternative roofing system manufacturers, CA Building Products (CABP) supply all the materials and components that are used within the complete roof assembly, including all internal liners (metal and rooflight), spacer system, insulation, all external profiles (metal and rooflight), as well as all fixings, sealants, fillers and the proprietary components required as part of the system assembly. No deviation from this is permitted, and all components must be procured and ordered through CABP to ensure full suitability and traceability.  

In addition, all installers must be trained (free-of-charge) in the correct installation of CABP systems, and a team of CA Group Field Services Engineers provide periodic support and site inspections throughout product installation to ensure they are installed according to the guarantee and HSE requirements. This training and on-site support gives genuine protection to both contractor and client, helping to drive up quality and ensure products will perform correctly for their entire guaranteed life.  

CA Group’s technical department rigorously tests the complete roofing system, inclusive of all Therma-light rooflights, over and above the requirements of the Advisory Committee for Roof safety standard ACR[M]001 ‘Test for Non-Fragility of Large Element Roofing Assemblies’. This testing is conducted on both the roof liner assembly in its own right, as well as the complete twin-skin roof system, and is carried out across all applicable purlin spans (up to a maximum of 1,800mm) and rooflight iterations. The completion of many hundreds of non-fragility tests over the last three decades has given CA Group the confidence to guarantee the non-fragility performance of the entire roofing system (inclusive of all Therma-light rooflight systems) for the entire duration of the roof system guarantee period when maintained in accordance with CA Group’s Guarantee requirements. 

This is a real discussion point in the industry at present due to the need to understand the risks of both installing, and then conducting maintenance on, rooftop PV systems throughout the building’s life. Typically, the majority of roof system manufacturers or rooflight manufacturers in the UK do not guarantee the non-fragility classification of the rooflight system within the associated roof assembly. Instead, they will allow cladding contractors to purchase the individual rooflight materials (GRP/Polycarbonate sheets, fixings, sealants, etc) directly with the individual component suppliers, or even substitute suppliers, if under commercial pressure. This then becomes a series of untested parts assembled on site by the cladding contractor, sometimes without clear direction as to the type or the locations of fixings and sealants needed to achieve specific non-fragility classifications when installing the rooflights within the metal roof. As such, the installer will generally rely on generic guidance, but this does not provide any guarantee that the rooflight as installed will be non-fragile. It also does not provide any long-term guarantee to the client or building owner that the rooflight remains safe for an extended period of time when maintained, with the majority of guidance based on the performance of the rooflights when new, rather than several years down the line when operatives are still accessing these roofs for inspection, maintenance, and cleaning.  

Making roofs safer for operatives and maintenance teams is of vital importance, especially as rooftop PV arrays and inverters often need to be accessed throughout the life of the building. CA Group has recently updated its installation guidance, which can be found by registering on its website at www.cagroup.co.uk/register.