Knauf receives second BBA certificate

Knauf receives second BBA certificate

Knauf Insulation’s Earthwool RainScreen Slab has received a second certificate from the British Board of Agrément (BBA), this time for use behind masonry.

The BBA certification applies to the use of Earthwool RainScreen Slab as partial fill thermal insulation on conventional steel-frame walls with a masonry outer leaf. It is suitable for use on both domestic and non-domestic buildings.

The new certification comes two months after Earthwool RainScreen Slab was certified by the BBA for use in high rise residential applications. This followed the December 2018 update to approved Document B, which mandated the use of non-combustible materials achieving a Euroclass Reaction to Fire Classification of A1 or A2 s1-d0 in the external walls of certain buildings over 18m in height. Earthwool RainScreen Slab has achieved the highest possible Euroclass Reaction to Fire classification of A1.

Luke Davies, Product Manager – Rock Mineral Wool at Knauf Insulation, explained: “This latest certification by the BBA demonstrates that Earthwool RainScreen Slab is a highly versatile insulation solution. As well as being non-combustible, Earthwool RainScreen Slab offers superior thermal performance making it the right choice for architects, specifiers and contractors.

“BBA certification ensures customers specifying or installing Earthwool RainScreen Slab can have absolute confidence in its quality and performance for buildings of any height or for any rainscreen application.”

Earthwool RainScreen Slab has a thermal conductivity of 0.034W/mK and features a water repellent additive to preserve its integrity while exposed during construction. It has been wind load tested by the Building Research Establishment to a maximum design pressure of 3,600Pa or 76m/s – the equivalent of a category 5 hurricane.

The improved robustness of the product reportedly makes it easier to manoeuvre in place, and is designed to adapt to minor imperfections in the substrate. It is manufactured using ECOSE® Technology, Kanuf’s patented bio-based binder which makes the manufacture of its products 70% less energy-intensive compared to mineral wool products made using traditional formaldehyde-based binders.

For more information on Earthwool RainScreen Slab, visit

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