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With ever increasing improvements demanded by the Building Regulations for the thermal efficiency of buildings, the need to specify effective insulation products within rainscreen cladding systems is of paramount importance.  Providing excellent levels of thermal, acoustic and fire performance, Knauf Insulation’s range of rock and glass mineral wool products are ideal for use in rainscreen cladding applications – supported by a 3D numerical modelling service.

Mineral wool insulation offers a number of advantages over rigid foam boards in rainscreen cladding applications and Knauf Insulation has a variety of glass and rock products, suitable for both steel frame and masonry buildings.  For example, Knauf Insulation’s Earthwool® RainScreen Slab is a rock mineral wool slab containing a water repellent additive, designed for use on masonry wall constructions and as the outer insulation layer in steel frame projects. 

Knauf Insulation’s Earthwool RainScreen Slab is quick and easy to install, and it is simple to cut and fit around brackets.  The slabs knit together to create a snug fit, with no need to tape the joints as is required with rigid foam boards – ensuring maximum acoustic and thermal performance, with no air gaps.

Knauf Insulation also provides 3D numerically modelled U-value calculations in line with BS EN ISO 10211 thereby ensuring the thermal performance of the rainscreen cladding system is accurately calculated. For thermal calculations that have not been calculated by numerical analysis in accordance with BS EN 10211-2007, a default correction of 0.30 W/m2K needs to be added to the calculated U-value.  Knauf Insulation’s 3D modelling calculations are provided by its Technical Advice and Support Centre (TASC).

Fire and acoustic performance should also be key considerations when specifying insulation for a rainscreen cladding system.  Approved Document B states that external insulation in any building of 18 metres or more (approximately seven storeys) should be of limited combustibility.  Knauf Insulation’s Earthwool RainScreen Slab is non-combustible and has the highest Euroclass A1 reaction to fire rating, as well as having excellent sound absorption performance.

In addition to Earthwool RainScreen Slab Knauf Insulation also manufactures Earthwool SteelTherm Roll 40 and Earthwool Flexible Slab, which have been developed for use in light steel frame constructions.  Both products are designed to friction fit between steel studs without needing to be cut on site.

Maria Morgan, market manager – non residential at Knauf Insulation, commented: “Mineral wool is the perfect insulation material for rainscreen cladding systems as it is easy to install, delivers significant thermal and acoustic performance and is non-combustible, therefore meeting the requirements of the Building Regulations.   Our range of rainscreen cladding products are rigorously tested and the solutions are fully backed up by sophisticated 3D thermal modelling techniques, so specifiers know they can rely on the quality and performance of our products within the system.”

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