220mm Rockwool EWI External Wall DD Slab

220mm Rockwool EWI External Wall DD Insulation Slab delivers premium thermal protection for external wall insulation systems with established third-party certification.

The 220mm Rockwool Dual Density construction features a robust high-density outer layer paired with a flexible lower-density core. This innovative design creates a durable surface for render and fixture installation whilst accommodating substrate variations. When installed with tight butt joints, the slabs interlock to form a continuous thermal barrier, eliminating heat loss through gaps.

Specifying 220mm Rockwool DD insulation in an External Wall Insulation (EWI) system provides proven long-term performance. Stone wool insulation delivers exceptional durability with a proven track record exceeding 55 years.*

Product specification

• Brand: Rockwool®
• Model: 220mm EWI
• Thickness: 220mm
• Dimensions: 1,200mm x 600mm x 220mm
• 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 220mm Rockwool External Wall Dual Density Slab combines precision engineering with practical performance for external wall applications. These 220mm external wall insulation boards utilise a distinctive dual density structure with two wool layers of varying densities: a softer lower layer accommodating minor surface imperfections, and a reinforced top layer ideal for render application. Installation requires metal pin mechanical fixings alongside quality adhesive, with a minimum of 7 fixings per square metre recommended.

Application

Install 220mm Rockwool Mineral Wool insulation slabs according to manufacturer guidelines covering design and installation procedures. For optimal adhesion, secure boards to the substrate using mortar/adhesive combined with mechanical fixings.

Given mineral wool's increased mass, the EWI-225 Premium Basecoat is preferable to standard adhesives suited for lighter materials. Apply a thin primer coat of adhesive to the prepared surface. After curing, apply the basecoat and set the Fibreglass Mesh.

Non-combustible

220mm Rockwool stone wool achieves the highest 'A1 – Non-combustible' rating under the European Reaction to Fire Classification System, guaranteeing it will not ignite or accelerate fire spread.

Durable

1. 220mm Rockwool DD slabs preserve dimensional stability throughout the building's lifecycle, resisting shrinkage and deterioration.
2. The reinforced outer surface enables secure basecoat bonding and prevents fastener over-driving.
3. Delivers superior resistance to wind and rain exposure during construction phases.
4. Proven performance: 220mm Rockwool has been integral to EWI systems across Europe for over 40 years.

Breathable

• 220mm Rockwool stone wool features an open-cell breathable structure permitting vapour transmission whilst water-repellent fibres prevent moisture penetration.
• Provides vapour resistance equivalent to still air.

Thermal performance

Closely butted slabs enable fibre interlocking, preventing thermal loss through gaps in the insulation layer.

Acoustic performance

• EWI systems using 220mm Rockwool slabs increase building envelope mass, reducing sound and vibration transmission.
• The fibrous material enhances sound absorption, with testing showing up to 8 dB improvement in weighted sound reduction, Rw (varies by substrate).

Dual Density Slabs for External Walls

• Purpose-engineered for external wall insulation systems, Dual Density Slabs provide a stone wool insulation option.
• Manufactured using ROCKWOOL's proprietary dual density process, these slabs incorporate a higher density top layer relative to the core. This delivers a robust render and fixture surface whilst the flexible lower layer adapts to substrate inconsistencies.
• The top layer is marked 'THIS SIDE UP' for straightforward installation and clear outer surface identification.

More Information on 220mm Rockwool External Wall DD Slab

• Manufacturer Link: Rockwool DD
• 220mm Rockwool External Wall DD Slab is a high-performance solution for diverse insulation requirements.
• Browse our full Rockwool Insulation range and refine by thickness or coverage using the left-hand filters. For project-specific advice or volume discount quotations, contact us on +4402038839057 , email sales@insulationbee or use Live Chat - Competitive UK Rockwool Insulation Pricing.