90mm Rockwool Dual Density Slab is a rigid thermal insulation slab specifically created for external wall applications to go directly under render.  It is made from volcanic rock, thus extremely durable and fire resistant.  The higher density outer surface of the slab is to take the render, whilst the resilient inner surface accommodates itself to irregularities in the surface of the substrate, thus maximising thermal performance.  The slabs will knit together when tightly butt jointed preventing extraneous heat loss. This also prevents water transmission through the insulation layer. These slabs can be used in conditions of severe climatic exposure. The slabs are made from 97% recyclable and renewable material which also makes them environmentally friendly since they can lower the carbon footprint of the household.

Rockwool Dual Density Insulation Slab is specifically made for external wall applications to go directly under render.