Rockwool 80mm High Performance Partial Fill Cavity Slab

The Rockwool 80mm High Performance Partial Fill Cavity Slab is a semi-rigid mineral wool solution engineered for masonry and framed cavity wall construction.

Achieving a Euroclass A1 non-combustible rating, this 80mm cavity wall insulation combines thermal performance with practical installation benefits. The dual-density structure accommodates surface irregularities on the inner leaf whilst offering a robust outer face for clip retention. This design maximises the lifespan of external wall systems by eliminating insulation voids and reducing unwanted heat transmission.

Product specification

• Thickness: 80mm
• 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 80mm Partial Fill Cavity Slab

• Perfect for masonry and framed cavity walls in multi-storey residential and commercial buildings.
• Non-combustible mineral wool with Euroclass A1 fire rating for enhanced safety.
• Delivers superior thermal performance and energy efficiency improvements.
• Water-resistant with a reinforced front surface that withstands impact and maintains integrity.
• Interlocking edges seal gaps effectively, preventing thermal bridging and heat escape.
• Semi-rigid construction enables straightforward installation and long-term reliability.
• Dimensions: 1200mm x 455mm x 80mm.
• Pallet coverage reaches 43.68m².
• Thermal conductivity of 0.34 W/mK ensures excellent insulation properties.
• Approved for all exposure zones where residual cavity width is 80mm or greater. In severe exposure conditions, external render finishes may be required in accordance with building standards.

Applications

Buildings up to and including 12 metres:

• Suitable for any exposure zone maintaining a residual cavity width of 80mm or greater. External render coats or equivalent finishes remain necessary in severe exposure zones as per standard practice.
• During installation, preserve a minimum residual cavity width of 25mm. Greater nominal cavity widths may be specified at design stage to account for construction tolerances. NHBC guidance recommends 80mm nominal cavity width under normal tolerance and workmanship standards.

Buildings over 12 metres in height: For structures exceeding 12 metres, maintain a minimum residual clear cavity width of 80mm with these requirements:

• Continuous cavity walls from ground 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 cases.
• Where cavity width reduces for structural reasons (such as ring beam intrusion), maintain a minimum residual cavity width of 25mm. Enhanced attention to fixings and weatherproofing, including cavity trays, is essential.

Benefits

Rockwool 80mm Partial Fill Cavity Insulation delivers a stable, long-lasting solution for thermal insulation of external walls.

Like natural stone, 80mm Rockwool Partial Fill Cavity stone wool insulation offers inherent durability. With a proven lifespan exceeding 65 years, performance remains consistent regardless of weather, moisture, temperature fluctuations or settlement—requiring no ongoing maintenance or specialist intervention.

More Information on 80mm Partial Fill Cavity Slab

• Manufacturer Link: Rockwool Twin Roll
• This high-performance product delivers reliable thermal insulation across diverse applications.
• Explore our complete Rockwool Insulation range and refine by thickness or coverage using the filters provided. For technical advice on product suitability, quantity discounts, or custom quotations, contact our team on +4402038839057, email sales@insulationbee, or use Live Chat for competitive Rockwool Insulation pricing.