Rockwool 170mm High Performance Partial Fill Cavity Slab

The Rockwool 170mm 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 170mm partial fill cavity insulation combines thermal efficiency with straightforward installation. The dual-density design accommodates surface irregularities on the inner leaf whilst providing a robust outer face for clip retention. This construction method significantly improves external wall durability, maintaining long-term energy performance and eliminating thermal bridging through continuous coverage.

Product specification

• Thickness: 170mm
• Length: 1200mm
• Width: 455mm
• Board Coverage: 0.546
• Pack Coverage: 2.18 m2
• Pack Quantity: 4
• 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 170mm Partial Fill Cavity Slab

• Suitable for masonry and framed cavity walls in all building types, including high-rise structures.
• Non-combustible classification with Euroclass A1 fire rating for enhanced safety standards.
• Delivers superior thermal performance and contributes to improved energy efficiency ratings.
• Water-resistant with a reinforced facing to prevent damage and extend product lifespan.
• Interlocking edges seal gaps effectively, reducing thermal loss throughout the cavity.
• Semi-rigid construction ensures quick installation and long-lasting structural integrity.
• Dimensions: 1200mm length x 455mm width x 170mm thickness.
• Pallet coverage reaches 21.84m² for efficient project planning.
• Thermal conductivity of 0.34 W/mK delivers reliable insulation performance.
• Approved for all exposure zones where residual cavity width is 170mm or greater. In severe exposure conditions, external render systems or equivalent weatherproofing may be required in accordance with building standards.

Applications

Buildings up to and including 12 metres:

• The product performs in any exposure zone provided a minimum residual cavity width of 170mm is maintained. In severe exposure zones, external render coats or similar protective finishes are typically applied following standard construction practices.
• The minimum residual cavity width during construction must be 25mm. A larger nominal cavity width may be specified during design to account for normal building tolerances. The NHBC, for example, recommends a nominal residual cavity width of 80mm under standard tolerance conditions.

Buildings over 12 metres in height: For structures exceeding 12 metres, maintain a minimum residual clear cavity width of 170mm with these requirements:

• Continuous cavity walls from ground level must not exceed 12 metres in height.
• Above 12 metres, continuous cavity walls should not surpass 7 metres in height.
• Continuous horizontal cavity trays discharging externally are mandatory in both cases.
• Where cavity width is reduced due to structural elements such as ring beams, a minimum residual cavity width of 25mm must be preserved. Enhanced attention to fixings and weatherproofing, including cavity trays, is essential.

Benefits

Rockwool 170mm Partial Fill Cavity Slab delivers a reliable and robust solution for thermal insulation of external wall systems.

Like natural stone, 170mm Rockwool Partial Fill Cavity stone wool insulation offers inherent durability. With a proven lifespan exceeding 65 years, performance remains consistent regardless of weather exposure, moisture levels, temperature fluctuations or compression—requiring no ongoing maintenance or specialist refurbishment.

More Information on 170mm Partial Fill Cavity Slab

• Manufacturer Link: Rockwool Twin Roll
• Rockwool 170mm Partial Fill Cavity Slab represents premium performance across diverse applications.
• Browse our complete Rockwool Insulation range and refine by thickness or coverage using the left-hand filters. For product suitability advice or bulk quotations, contact us on +4402038839057 , email sales@insulationbee or use Live Chat - Competitive UK Rockwool Insulation Pricing.