150mm Rockwool EWI External Wall Dual Density Slab

150mm Rockwool EWI External Wall DD Insulation Slab delivers professional-grade thermal performance for wall insulation applications across externally applied systems with third-party certification.

Manufactured using Rockwool's innovative Dual Density technology, these slabs combine a reinforced outer layer with a flexible inner core. The high-density surface provides excellent stability for rendering and fixture installation, whilst the softer underside accommodates substrate variations and imperfections.

When installed with tight joints, the slabs create a unified thermal envelope that eliminates heat loss through gaps and thermal bridging.

Specifying 150mm Rockwool DD insulation in an External Wall Insulation (EWI) system guarantees reliable long-term performance. Stone wool insulation delivers proven durability, with documented performance extending beyond 55 years.*

Product specification

• Brand: Rockwool®
• Model: 150mm EWI
• Thickness: 150mm
• Dimensions: 1,200mm x 600mm x 150mm
• Length: 1200mm
• Width: 600mm
• Board Coverage: 0.72m2
• Colour: Pale white
• Density: 110kg/m3
• Compressive strength: ≥ 10 kPa
• Tensile strength: ≥ 10 kPa
• R-Value: 1.39m2K/W
• Thermal Conductivity: 0.036W/mK
• Material: Molten volcanic rocks
• Profile: Square edge
• Temperature resistance: up to 1000ºC
• Fire Classification: A1 Non-combustible
• Shipping method: Articulated Vehicle ǀ Courier
• Applications: External Wall Insulation Systems
• Features: Thermal and Acoustic Insulation Slab
• Manufacturer: ROCKWOOL®

The 150mm Rockwool External Wall Dual Density Slab represents engineered excellence for external wall insulation projects. These 150mm external wall insulation boards feature distinctive dual-layer construction with contrasting wool densities: a lower-density base layer that accommodates building fabric variations, and a premium-density upper layer optimised for render application. Installation requires metal pin mechanical fixings supplemented with high-performance adhesive, with a minimum of 7 fixings per square metre recommended for structural integrity.

Application

150mm Rockwool Mineral Wool insulation slabs must be installed according to manufacturer guidelines, including design specifications and application protocols. For optimal adhesion, secure boards to the substrate using mortar-based adhesive combined with mechanical fixings.

Given the substantial weight of mineral wool products, we recommend applying the EWI-225 Premium Basecoat instead of standard adhesive formulations designed for lighter materials. Apply a thin, diluted adhesive layer to the prepared surface first. After curing, apply the basecoat and set the Fibreglass Mesh into position.

Non-combustible

150mm Rockwool stone wool achieves the highest European Reaction to Fire Classification rating of A1 – Non-combustible, meaning it will not ignite or support fire propagation.

Durable

1. 150mm Rockwool DD slabs preserve dimensional stability throughout the building's operational life, resisting shrinkage and material degradation.
2. The reinforced outer surface enables secure basecoat adhesion and prevents fastener over-driving.
3. Demonstrates exceptional resistance to wind and rain exposure during the installation phase.
4. Proven track record: 150mm Rockwool has performed reliably in EWI systems throughout Europe for more than 40 years.

Breathable

• 150mm Rockwool stone wool features an open-cell structure that permits water vapour transmission, whilst hydrophobic fibres prevent water penetration.
• Provides vapour resistance equivalent to still air conditions.

Thermal performance

Slabs installed with tight butt joints allow fibres to interlock effectively, preventing heat losses through gaps and thermal discontinuities in the insulation layer.

Acoustic performance

• Buildings with 150mm Rockwool slabs integrated into EWI systems benefit from enhanced envelope mass that suppresses sound and vibration transmission.
• The fibrous material composition contributes to sound absorption, with testing confirming improvements of up to 8 dB in weighted sound reduction, Rw (depending on substrate conditions).

Dual Density Slabs for External Walls

• Purpose-engineered for external wall insulation systems, Dual Density Slabs deliver stone wool insulation performance.
• Manufactured using ROCKWOOL's proprietary dual density process, these slabs incorporate a higher-density upper layer relative to the core. This construction delivers a robust surface for rendering and fastening, whilst the adaptable lower layer accommodates substrate surface variations.
• Installation is simplified by clear 'THIS SIDE UP' marking on the top layer, enabling quick identification of the correct orientation.

More Information on 150mm Rockwool External Wall DD Slab

• Manufacturer Link: Rockwool DD
• 150mm Rockwool External Wall DD Slab is a premium performance product delivering diverse application possibilities.
• Explore our complete Rockwool Insulation range and refine your selection by thickness or coverage using the filters on the left. For expert guidance on product suitability for your specific project, or to request a volume discount quotation, contact us by phone on +4402038839057, email sales@insulationbee, or use Live Chat - Competitive UK Rockwool Insulation Pricing.