90mm Rockwool TCB Cavity Barrier and PWCB Cavity Barrier products deliver superior fire protection for timber frame and masonry constructions. These barriers exceed minimum building regulation standards for fire resistance in concealed wall cavities, with proven performance up to 60 minutes of integrity and insulation.
Manufactured from non-combustible stone wool and wrapped in protective polythene sleeves, these cavity wall insulation products provide thermal and weather protection during fitting. Colour-coded sleeves—red for TCB and white for PWCB—enable quick identification on site.
The Rockwool cavity barrier combines fire safety, acoustic flanking control, and thermal bypass prevention in one product. It also seals perimeter edges to minimise air infiltration and reduce unwanted heat loss.
The 90mm Rockwool TCB Cavity Barrier works effectively in both vertical and horizontal installations. For vertical applications, secure the flanges to the inner leaf at 150mm intervals using staples or clout nails before the outer cavity wall compresses the barrier. In horizontal applications, fix only the top flange of the polythene sleeve.
Euroclass A1 fire rating: ROCKWOOL Cavity Barriers meet the highest fire safety standards and have been tested and assessed for up to 60 minutes of fire resistance (both integrity and insulation) in accordance with BS 476: Part 20.
The 90mm Rockwool TCB Cavity Barrier and PWCB Cavity Barrier have been engineered to exceed minimum Building Regulation requirements for fire resistance in concealed wall cavities.
These barriers remain unaffected by building movement, shrinkage, or thermal fluctuations, maintaining reliable performance throughout the building's lifespan.
Designed for robust on-site handling, these barriers provide lifetime protection once installed, safeguarding your structure for decades to come.
ROCKWOOL Cavity Barriers adapt to both vertical and horizontal applications. In vertical installations, both flanges can be fastened to the inner leaf at 150mm intervals, whilst horizontal applications require only the top flange to be secured.
ROCKWOOL Cavity Barriers effectively block flanking noise transmission through concealed cavities in external wall insulation and separating walls, enhancing acoustic comfort throughout the building.








