Stone wool could be a game-changer for making lightweight timber-framed construction more fire-safe. It comes as a series of tests at the CSIRO North Ryde facility confirmed that timber-framed walls covered with stone wool can burn for two and a half hours or more, easily surpassing the 45-minute threshold for external walls specified under Australia’s National Construction Code’s fire-protected timber requirements.
This test represents a significant advancement in building materials technology, offering architects, engineers, and builders a promising alternative to traditional fire protection methods. The findings suggest that stone wool could become a transformative solution for fire safety and efficiency in lightweight timber frame construction with tremendous application to the fire resistance of timber-framed mid-rise buildings as well as the fire protection of houses in bushfire flame zones.
Andrew Dunn – CEO of the Timber Development Association – who said the tests now offer architects, engineers and builders a promising alternative to traditional fire protection.
Wood Central understands that the AS 1530.4 tests, conducted with support from DCTech, Forest Wood Products Australia, pro clima, NeXTimber® by Timberlink, ROCKWOOL Australia, and Xlam Australia, saw researchers test a 90 mm x 75mm timber frame covered with 75 mm of ROCKWOOL and DCTech VulchWool.
Dunn said the primary goal of the test was to assess the panels’ fire resistance by measuring the interface temperature between the stone wool and timber: “The standard requires the temperature to remain below 300°C for critical durations—45 minutes for external walls, 20 minutes for stairways, lofts and shafts, and 30 minutes for all other areas,” according to a statement attributed to the Timber Development Association.
Stone wool is also transformative for safer and more cost-effective mass timber
The new results come months after a round of AS 1530.4 tests – this time using 140mm cross-laminated timber panels split evenly as NeXTimber® by Timberlink, and Xlam Australia – showed that over 50% of panels that use 50mm of stone wool on the underside of the timber remained intact for three hours after burning.
“Over the years, I’ve observed numerous mass timber tests, but the stone wool performance was extraordinarily impressive. It easily outperformed traditional
fire-grade plasterboard,” Dunn said. “Stone wool provides superior fire protection while simultaneously delivering excellent acoustic and thermal insulation. This could potentially revolutionise construction costs for mass timber buildings.”
- To find out why developers and certifiers are increasingly turning to timber in construction, click here for Wood Central’s special feature.
