Rockwool mineral wool boards are mostly made from volcanic ash and are manufactured with a special water repellant additive for exterior use.
We prefer Knauf Rocksilk boards as they are high quality and have a crimped surface to aid the backing render that is trowelled on to them.
These boards have the following characteristics:
CFC free – environmentally friendly
High Density – so good impact resistance
Class 1 Fire Resistance
Vapour permeable – highly breathable
40mm to 300mm thickness available
60mm depth = 0.43 U value on 9 inch solid walls
Suitable for mineral and silicate modern render systems