A bright refurbishment and extension for Shawbury Primary School
18th December 2017
Wetherby EWI – Brick Effect Insulated Render in Hartlebury, Worcestershire
16th January 2018
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Non-combustible cladding

External Wall Insulation provides solutions to the modern construction market for thermal and aesthetic refurbishment of domestic and social dwellings, as well as commercial properties. New construction methods also utilise EWI systems for ‘Fastrack’ building systems, improving programming and realising financial efficiencies.

Since its rise to prominence in the UK, thermal performance is well documented. However, fire performance of the Mineral Wool Systems has sometimes been overlooked. Mineral Wool Systems generally achieve A1 Class O Fire Performance as standard and thus eliminating the risk of the spread of fire.

The overriding principle of fire management is that once a fire develops it is contained and it should not spread throughout the building, either internally or across the building façade.

There are essentially two distinct classes of cladding systems for building facades:

(1) Those that include a cavity between a decorative/protective cladding and the wall insulation. These are generally referred to as rain screen or back-ventilated systems.

(2) Those which are directly attached to the wall face and which are ‘face-sealed’ to prevent weather penetration. This latter class includes our type of product: external wall insulation with render finishes, often referred to as insulated render systems.

To ensure fire safety, a cladding system must be designed to prevent the spread of fire. This usually necessitates that the insulation is classed as ‘non-combustible’ (e.g. stone wool / Rockwool) or, if the insulation is not non-combustible, the system must incorporate fire barriers within the insulation so that, in the event of a fire entering into the cladding system, the fire is prevented from spreading through the cavity. Fire stopping measures within the cavity are essential and cladding materials must have appropriate fire resistance properties.

Mineral wool EWI systems have been designed to satisfy the fire performance requirements of the buildings onto which they are applied. For example, Permarock systems have specialised in Mineral Wool EWI systems for over twenty years. Carrying supporting data and certification of performance for both direct fix Mineral Wool Systems, as well as Cavity Rail EWI Systems.

Should you require any further information on fire strategy and performance, we are happy to co-ordinate communications with the relevant technical departments of our partners.


For more information please click through to the Building Research Institute.



Example of a completed project with Non combustible EWI – Metal frame construction

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