Rockwool Building Roll Rockwool Building Rolls is used mainly in pre-engineered buildings for roofs and walls to achieve excellent thermal and acoustic insulation. It can be used for both under purlin and over purlin application on the roof. Stone wool fibers in Rockwool Building Rolls are fine and uniformly distributed that ensures excellent & uniform thermal resistance. The stable stone wool fibers bonded with thermosetting resins are light in weight, strong and resilient. FACING TYPES Rockwool Building Rolls are available with ALG and FSK facings, which provide an efficient vapour barrier. The product is also available with kraft paper facing. WORKING TEMPERATURE Fiber : Up to 750°C Facing : 100°C At temperatures in excess of 230°C a limited migration of binder may occur in the insulation in contact with the hot face. This does not impair the insulation performance.