140mm Rockwool TCB Cavity Barrier and PWCB Cavity Barrier solutions deliver outstanding fire protection for timber frame and masonry constructions. These products are engineered to surpass building regulation standards for fire resistance in concealed wall cavities, with proven performance ratings of up to 60 minutes for both integrity and insulation.
Manufactured from non-combustible stone wool and wrapped in protective polythene sleeves, these cavity wall insulation barriers provide thermal performance and weather protection throughout the installation process. Colour-coded sleeves—red for TCB and white for PWCB—make identification straightforward on site.
The Rockwool cavity barrier combines fire safety, acoustic flanking control, and thermal bypass prevention into one integrated product. It also seals perimeter edges effectively, minimising air infiltration and reducing unwanted heat loss.
The 140mm Rockwool TCB Cavity Barrier performs excellently in both vertical and horizontal orientations. For vertical installations, secure both flanges to the inner leaf at 150mm intervals using staples or clout nails before the outer cavity wall compresses the product. 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 140mm Rockwool TCB Cavity Barrier and PWCB Cavity Barrier range exceeds minimum Building Regulation requirements for fire resistance in concealed wall cavities, delivering superior protection.
These barriers remain unaffected by building movement, timber shrinkage, or temperature fluctuations, maintaining reliable performance throughout the building's lifespan.
Designed for robust on-site handling, these products provide permanent protection once installed, safeguarding the structure for its entire operational life.
ROCKWOOL Cavity Barriers adapt to both vertical and horizontal applications. Vertical installations allow both flanges to be fastened to the inner leaf at 150mm intervals, whilst horizontal applications require only the top flange of the polythene sleeve to be secured.
ROCKWOOL Cavity Barriers effectively suppress flanking noise transmission through concealed cavities in both external wall insulation and separating walls, enhancing acoustic comfort throughout the building.








