230mm Rockwool EWI External Wall Dual Density Slab

230mm Rockwool EWI External Wall Dual Density Insulation Slab delivers superior thermal performance for external wall insulation systems with established third-party certification.

Manufactured using Rockwool's innovative Dual Density technology, these slabs feature a reinforced outer layer with enhanced density paired with a flexible inner core. This combination provides an exceptionally robust surface for render application and fixture installation, whilst the softer underside accommodates substrate variations and imperfections.

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

Specifying 230mm Rockwool DD insulation within an External Wall Insulation (EWI) system provides building owners with proven long-term reliability. Stone wool insulation from Rockwool demonstrates exceptional durability, with documented performance spanning over 55 years.*

Product specification

• Brand: Rockwool®
• Model: 230mm EWI
• Thickness: 230mm
• Dimensions: 1,200mm x 600mm x 230mm
• Length: 1200mm
• Width: 600mm
• Board Coverage: 0.72m2
• Colour: Pale white
• Density: 110kg/m3
• Compressive strength: ≥ 10 kPa\t
• 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 230mm Rockwool External Wall Dual Density Slab is engineered for exceptional performance in external wall insulation applications. These 230mm external wall insulation boards incorporate a distinctive dual density construction with two separate wool layers of differing densities: a softer lower density layer that accommodates minor substrate imperfections, and a harder upper density layer that creates the perfect foundation for render application. Installation of these 230mm Rockwool external wall insulation boards requires mechanical metal pin fixings combined with high-performance adhesive. A minimum of 7 fixings per square metre is essential for reliable installation.

Application

230mm Rockwool Mineral Wool insulation slabs must be installed according to manufacturer guidelines, which detail design specifications and application procedures. For optimal adhesion strength, secure the boards to the substrate using mortar/adhesive together with mechanical fixings.

Given the substantial weight of Mineral Wool, we recommend applying the EWI-225 Premium Basecoat instead of standard adhesive formulations designed for lighter insulation products. Start with a thin, diluted adhesive layer on the prepared surface. After curing, apply the basecoat and position the Fibreglass Mesh into the wet coat.

Non-combustible

230mm Rockwool stone wool achieves the highest 'A1 – Non-combustible' rating under the European Reaction to Fire Classification System, meaning it will not ignite or accelerate fire spread.

Durable

1. 230mm Rockwool DD slabs maintain consistent dimensions throughout the building's lifespan, resisting any shrinkage or material degradation.
2. The reinforced outer surface enables secure basecoat adhesion and prevents fastener over-driving.
3. Demonstrates exceptional resistance to wind and rain damage during the construction phase.
4. Proven and reliable: 230mm Rockwool has been the preferred choice for EWI systems throughout Europe for more than 40 years.

Breathable

• 230mm Rockwool stone wool's open-cell breathable structure allows water vapour to pass through, whilst its water-resistant fibres prevent moisture penetration.
• Provides vapour resistance equivalent to still air.

Thermal performance

Slabs installed with tight butt joints allow fibres to interlock efficiently, preventing thermal losses through gaps and weak points in the insulation layer.

Acoustic performance

• External wall insulation systems using 230mm Rockwool slabs enhance the building envelope's mass, reducing sound and vibration transmission.
• The fibrous material structure contributes to sound dampening, with test data showing sound reduction improvements of up to 8 dB in weighted sound reduction, Rw (depending on substrate conditions).

Dual Density Slabs for External Walls

• Purpose-built for external wall insulation systems, Dual Density Slabs deliver a premium stone wool insulation solution.
• Manufactured using ROCKWOOL's proprietary 'dual density' process, these slabs incorporate a denser upper layer compared to the remainder of the product. This delivers a durable surface suitable for render application and fixture attachment, whilst the softer lower layer flexes to accommodate substrate variations.
• For straightforward installation, the top layer is clearly marked 'THIS SIDE UP', making it simple to identify the correct outer surface.

More Information on 230mm Rockwool External Wall DD Slab

• Manufaturer Link: Rockwool DD
• 230mm Rockwool External Wall DD Slab is a premium-quality product delivering reliable performance across diverse applications.
• Browse our complete Rockwool Insulation range and refine by thickness or coverage using the filters on the left. For advice on product suitability for your specific project, or to request a bulk discount quotation, contact us on +4402038839057 , email sales@insulationbee or use Live Chat - Competitive UK Rockwool Insulation Pricing.