Construction company Willmott Dixon has announced it has successfully commissioned fire safety tests for cavity barriers on Cross-Laminated Timber (CLT) to “eliminate a technical gap that has created uncertainty and delays on CLT projects across the sector”
Performed alongside Siderise, a passive fire protection specialist, and KLH, a CLT manufacturer, the testing programme has been described as a “turning point” for timber construction in the UK. It aims to eliminate the need for individual technical assessments by providing the industry with certified solutions for projects that utilise CLT and Siderise cavity barriers in wall and floor applications.
As Willmott Dixon explains, the use of CLT in construction provides considerable carbon benefits compared to traditional construction materials. However, “technical uncertainties around fire safety details have historically slowed design processes and created risk for project teams”.
“The absence of standardised testing for cavity barriers on CLT has meant that every project required bespoke technical assessments, creating inefficiency in design processes and uncertainty around fire safety performance. The new test data provides design teams across the sector with certified solutions that can be specified with confidence,” the construction company said.
Three “critical interface scenarios” were tested, covering CLT floor and wall interfaces in vertical and horizontal configurations. They also covered “worst-case scenarios” with CLT panels tested to “rigorous European standards”.
Jessica Winyard, Architectural Technologist at Willmott Dixon, said: "This testing addresses a genuine technical gap that affects every organisation working with CLT.
“By working collaboratively with Siderise and KLH to develop these solutions, we're helping to accelerate the adoption of low-carbon construction methods while ensuring robust fire safety performance.”
Director of Testing & Project Engineering at Siderise, Chris Mort, added: "One of the primary goals of investing in the Siderise Innovation Centre was to provide the industry with the means to back their designs with robust test data, helping them achieve compliance and deliver safer buildings without compromising on design.
“We were delighted to support Willmott Dixon with the development of standard details for the CLT projects, and our learning from this process has been invaluable for expanding our own understanding of the demands of such an innovative structural system.”
Willmott Dixon hopes that the tests can benefit architects, engineers, and contractors using CLT in their projects, supporting the wider adoption of CLT in construction projects.
More details of the testing programme can be found here.