90mm Rockwool External Wall DD Insulation Slab

90mm Rockwool EWI External Wall DD Insulation Slab delivers dependable thermal protection for wall insulation systems with established third-party certification.

Engineered with Rockwool's Dual Density technology, this 90mm slab features a reinforced outer layer and softer inner core. The dense top surface provides excellent support for render and fixture installation, whilst the flexible base accommodates substrate variations without compromise.

When installed edge-to-edge, the slabs create an unbroken thermal envelope, eliminating heat transfer through joints and cracks.

Specifying 90mm Rockwool DD in an External Wall Insulation (EWI) system guarantees reliable long-term performance. Stone wool insulation from Rockwool delivers proven durability, with documented performance spanning 55+ years.*

Product specification

• Brand: Rockwool®
• Model: 90mm EWI
• Thickness: 90mm
• Dimensions: 1,200mm x 600mm x 90mm
• 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 90mm Rockwool External Wall Dual Density Slab combines precision engineering with proven performance for external wall applications. These 90mm external wall insulation boards showcase dual density construction with two distinct wool layers of varying density: a lower density core for accommodating minor substrate imperfections, and a high-density outer layer ideal for render application. Installation requires mechanical fixings combined with quality adhesive—a minimum of 7 fixings per square metre ensures secure attachment.

Application

Install 90mm Rockwool Mineral Wool insulation slabs following manufacturer guidelines for design and installation specifics. Achieve optimal adhesion by combining mortar or adhesive with mechanical fixings for substrate attachment.

Given mineral wool's substantial weight, the EWI-225 Premium Basecoat is recommended over standard adhesives for lighter materials. Apply a thin primer coat to the prepared substrate, allow drying, then apply the basecoat and embed the Fibreglass Mesh.

Non-combustible

90mm Rockwool stone wool achieves the highest A1 rating in European fire classification, meaning it will not ignite or contribute to flame spread.

Durable

1. 90mm Rockwool DD slabs maintain dimensional stability throughout the building's lifespan, resisting shrinkage or degradation.
2. The dense outer surface enables secure basecoat application and prevents overdriven fixings.
3. Demonstrates high resistance to wind and rain exposure during construction.
4. Proven track record: 90mm Rockwool has performed reliably in EWI systems across Europe for over 40 years.

Breathable

• 90mm Rockwool stone wool features an open-cell structure that permits water vapour transmission, whilst water-repellent fibres prevent moisture ingress.
• Provides vapour resistance equivalent to still air.

Thermal performance

Edge-to-edge installation allows fibres to interlock effectively, eliminating heat losses through gaps in the insulation layer.

Acoustic performance

• EWI systems using 90mm Rockwool slabs increase building envelope mass, reducing sound and vibration transmission.
• The fibrous material aids sound absorption, with testing showing up to 8 dB improvement in weighted sound reduction, Rw (dependent on substrate).

Dual Density Slabs for External Walls

• Purpose-designed for external wall insulation systems, Dual Density Slabs deliver stone wool insulation excellence.
• Manufactured using ROCKWOOL's patented dual density process, these slabs feature a higher density outer layer compared to the inner core. This creates a robust surface for render and fixture attachment, whilst the flexible underside adapts to substrate variations.
• The top layer is clearly marked 'THIS SIDE UP' for straightforward installation and correct orientation.

More Information on 90mm Rockwool External Wall DD Slab

• Manufacturer Link: Rockwool DD
• 90mm Rockwool External Wall DD Slab is a premium performer offering broad application versatility.
• Browse our full Rockwool Insulation range and filter by thickness or coverage on the left-hand side of the page. For advice on product suitability for your project or to request a quantity discount quotation, contact us by phone on +4402038839057, email sales@insulationbee or Live Chat - Best UK Rockwool Insulation Prices.