120mm Rockwool PWCB Cavity Barrier

120mm Rockwool PWCB Cavity Barrier delivers superior fire protection for timber frame and masonry construction. Engineered to exceed building regulation standards, this product provides up to 60 minutes of fire resistance in concealed wall cavities, backed by comprehensive testing and certification.

Manufactured from non-combustible stone wool and wrapped in protective polythene sleeves, this cavity wall insulation solution offers thermal performance alongside fire safety. 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 effectively, minimising air infiltration and reducing unwanted heat loss.

Product specification

• Thickness: 120mm
• Width: 200mm
• Length: 1200m
• Length Coverage: 1.2 LM (linear metre)
• Quantity: 1
• Also Available in packs of: 9
• Thermal Conductivity: 0.038 W/mK
• R-Value: 2.47 m²K/W
• Fire Rating: A1
• Fire Resistance: Up to 60 minutes

Key points

• Euroclass A1 non-combustible material.
• FLEXI Edge technology ensures secure friction fit.
• Outstanding acoustic, thermal, and fire protection performance.
• Resists slumping even when timber studs shrink.
• Zero Ozone Depletion Potential (ODP) and Global Warming Potential (GWP).
• Simple installation process.
• Fire resistance up to 60 minutes (EI).
• Reduces acoustic flanking transmission.
• Minimises air leakage and heat loss.
• Unaffected by structural movement.
• Works for vertical and horizontal applications.
• Weather-protected and durable on site.

Application

120mm Rockwool PWCB Cavity Barrier suits 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 them. In horizontal applications, fix only the top flange of the polythene sleeve.

Certification

Euroclass A1 fire rating: ROCKWOOL Cavity Barriers meet the highest fire safety standards, tested and assessed for up to 60 minutes of fire resistance (integrity and insulation) to BS 476: Part 20.

• ISO14001: Compliant with Environmental Management standards.
• EN 13162: Manufactured to European standards.
• A+ rating on BRE Green Guide: Recognised for excellent environmental performance.

Fire Protection

120mm Rockwool PWCB Cavity Barrier exceeds minimum Building Regulation requirements for fire resistance in concealed wall cavities.

Resilient Performance

This cavity barrier remains unaffected by building movement, timber shrinkage, or thermal changes, maintaining consistent performance throughout the building's lifetime.

Durability

Designed to withstand on-site handling and installation stresses, this product delivers long-lasting protection for the full lifespan of the structure.

Vertical or Horizontal Solution

ROCKWOOL Cavity Barriers adapt to both vertical and horizontal applications. Vertical installations allow both flanges to be secured to the inner leaf at 150mm intervals, whilst horizontal applications require only the top flange of the polythene sleeve to be fixed.

Acoustic Protection

ROCKWOOL Cavity Barriers prevent flanking noise transmission along concealed cavities in external wall insulation and separating walls, enhancing acoustic comfort throughout the building.

More Information on 120mm Rockwool PWCB Cavity Barrier

• Manufacturer Link: 120mm Rockwool PWCB Cavity Barrier
• Browse our complete Rockwool Insulation range and filter by thickness or coverage on the left-hand side. For product suitability advice or quantity discount quotations, contact us by phone on +4402038839057, email sales@insulationbee, or use Live Chat for the lowest UK Rockwool Insulation prices.