150mm Rockwool PWCB Cavity Barrier products deliver outstanding fire protection for timber frame and masonry construction. These barriers exceed 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 barriers provide thermal and weather protection throughout installation. Colour-coded sleeves—red for TCB and white for PWCB—enable quick product 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 effectively, minimising air infiltration and heat loss.
The 150mm Rockwool PWCB Cavity Barrier works effectively in both vertical and horizontal configurations. For vertical installations, flanges attach securely to the inner leaf at 150mm intervals using staples or clout nails before the outer cavity wall compresses them. In horizontal applications, only the top flange of the polythene sleeve requires fixing.
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 150mm Rockwool PWCB Cavity Barrier exceeds minimum Building Regulation requirements for fire resistance in concealed wall cavities, delivering superior safety performance.
These barriers remain unaffected by building movement, shrinkage, or thermal changes, maintaining consistent protective performance throughout the building's lifespan.
Designed for robust on-site handling, these barriers provide lifetime protection once installed, safeguarding your structure against fire and thermal risks.
ROCKWOOL Cavity Barriers adapt to both vertical and horizontal applications. Vertical installations allow both flanges to secure to the inner leaf at 150mm intervals, whilst horizontal applications require only the top flange of the polythene sleeve to be fixed.
ROCKWOOL Cavity Barriers effectively block flanking noise transmission through concealed cavities in external wall insulation and separating walls, enhancing acoustic comfort throughout the building.








