Colour match fixings range launched for Rocksilk® Soffit Linerboard

By Knauf Insulation UK & Ireland
June 06, 2022

Knauf Insulation has partnered with Fixfast, the UK’s largest fastener manufacturer, to launch the first range of colour-matched tube washers to enhance the aesthetic appeal of its Rocksilk® Soffit Linerboard when installed.

“We know architects and contractors choose Rocksilk® Soffit Linerboard for use in car parks, stadiums and commercial units because it is a high-performing non-combustible insulation solution that looks great. While installers like it because no additional finishing is required,” said Luke Davies, Rock Mineral Wool Product Manager, Knauf Insulation.

To reduce thermal bridging, we developed a fixing method using tube washers in the corners of each slab instead of traditional all-steel fixings. But until now the washers have only been available in purple, so they really stand out”.

Rocksilk® Soffit Linerboard is available in two variants, Extra and Standard, depending on the finish and impact resistance required. To ensure fixings blend in, the new range includes fasteners with tube washers that are colour-matched to the off-white cementitious particle board of Extra and the matt black veil facing of Standard.

To streamline the order and delivery process, the colour-matched fixings can be ordered directly through Knauf Insulation when purchasing Rocksilk® Soffit Linerboard.

Rocksilk® Soffit Linerboard comes in four standard thicknesses between 50mm – 220mm and is also available in bespoke sizes up to 270mm. It has a thermal conductivity of just 0.034 W/mK – the lowest on the market for a Rock Mineral Wool soffit slab. An additional base layer can be used to meet build-up requirements.

As well as excellent thermal performance, Rocksilk® Soffit Linerboard has the best possible Euroclass A1 reaction to fire classification, so it will not contribute to the development or spread of a fire should it occur. It also has excellent sound absorption characteristics so it will provide high levels of sound reduction.

It is manufactured with ECOSE® Technology, Knauf Insulation's unique bio-based binder that contains no added formaldehyde or phenol. It is made from natural raw materials that are rapidly renewable and is 70% less energy-intensive to manufacture than traditional binders, so it is more environmentally friendly. Products made with ECOSE® Technology are soft to touch and easy to handle. They generate low levels of dust and VOCs and have been awarded the Eurofins Gold Certificate for Indoor Air Comfort. Using products manufactured with ECOSE® Technology can also help buildings earn points within green building rating systems, such as BREEAM and LEED.

Rocksilk® Soffit Linerboard can be installed directly into a pre-cast or composite steel deck from below. Enhanced rigidity improves the installation process because slabs are easier to manoeuvre into place. A detailed installation guide is also available, with clear and simple advice to installers for a wide range of applications and scenarios.

Visit for more information about Rocksilk® Soffit Linerboard.