50mm Rockwool Partial Fill Cavity Slab

The 50mm Rockwool High Performance Partial Fill Cavity Slab delivers a semi-rigid insulation system designed specifically for masonry cavity wall applications.

Achieving Euroclass A1 fire classification, this 50mm Rockwool cavity insulation combines thermal performance with straightforward installation. The dual-density structure accommodates surface irregularities on the inner leaf whilst presenting a robust outer face for clip retention. This construction method protects external wall systems, sustaining long-term energy performance and minimising heat loss through continuous insulation coverage.

Product specification

• Thickness: 50mm
• Length: 1200mm
• Width: 455mm
• Board Coverage: 0.546
• Pack Coverage: 4.37m2
• Pack Quantity: 8
• Thermal Conductivity: 0.034 W/mK
• Application: Cavity Wall Insulation
• Features: Fire Protection
• Fire Protection: Non-Combustible
• Material: Mineral Wool
• Application: Masonry and framed cavity wall construction
• Product standards: BS EN 13162
• CE Marking: CE Marked
• BBA Approved: Certificate 93/2884
• Water repellent: Yes
• Water vapour resistance: Negligible

Features & Benefits: ROCKWOOL Partial Fill Cavity Slab 50mm

• Perfect for masonry and framed cavity wall systems in residential and high-rise applications.
• Non-combustible construction with Euroclass A1 fire rating delivers exceptional fire safety performance.
• Maximises thermal efficiency for improved building energy ratings.
• Water-resistant with reinforced facing to prevent deterioration and extend product lifespan.
• Interlocking edges seal gaps effectively, reducing unwanted heat transfer.
• Semi-rigid 50mm partial fill insulation engineered for rapid installation and structural stability.
• Dimensions: 1200mm length x 455mm width x 50mm thickness.
• Delivers 65.52m² coverage per pallet.
• Thermal conductivity rating of 0.34 W/mK ensures reliable insulation performance.
• Approved for all exposure classifications with minimum 50mm residual cavity width. In high-exposure locations, external render finishes may be required in accordance with building standards.

Applications

Buildings up to and including 12 metres:

• The product performs in any exposure zone maintaining a residual cavity width of 50mm or greater. External render coats or comparable finishes should be applied in severe exposure zones as per standard construction practice, though this product alone does not eliminate such requirements.
• During installation, maintain a minimum residual cavity width of 25mm. To achieve this, specify a greater nominal residual cavity width at design stage to account for construction tolerances. The NHBC recommends a nominal residual cavity width of 50mm for standard tolerance and workmanship levels.

Buildings over 12 metres in height: For structures exceeding 12 metres, maintain a minimum residual clear cavity width of 50mm with these requirements:

• Continuous cavity walls from base level must not exceed 12 metres height.
• Above 12 metres, continuous cavity walls should not surpass 7 metres height.
• Continuous horizontal cavity trays discharging externally are mandatory in both scenarios.
• Where cavity width reduces for structural reasons such as ring beam intrusion, preserve a minimum residual cavity width of 25mm. Exercise additional care with fixings and weatherproofing measures, including cavity tray installation.

Benefits

50mm Rockwool Partial Fill Cavity Insulation provides a stable, long-lasting solution for thermal insulation of external wall systems.

Like stone, 50mm Rockwool Partial Fill Cavity stone wool insulation offers inherent durability. With a proven lifespan exceeding 65 years, performance remains constant regardless of weather exposure, moisture levels, temperature fluctuations or material compression—requiring no ongoing maintenance or replacement.

More Information on 50mm Partial Fill Cavity Slab

• Manufacturer Link: Rockwool Twin Roll
• 50mm Rockwool Partial Fill Cavity Slab represents premium cavity insulation with broad application scope.
• Explore our complete Rockwool Insulation range and refine selections by thickness or coverage using the sidebar filters. For project-specific guidance or bulk pricing enquiries, contact our team on +4402038839057 , email sales@insulationbee or use Live Chat - Competitive UK Rockwool Insulation Pricing.