Description
Rockwool Frontrock Super 80 mm is the entry slab in our dual-density Super range — a Euroclass A1 stone wool board engineered for facades that need impact resistance and non-combustible classification at the same time, supplied 3 slabs per pack covering 1.8 m². It is specified across exposed ground-floor zones, public-facing elevations, and multi-occupancy buildings where the project fire strategy and the wall's mechanical exposure both drive the material choice.
What Rockwool Super 80 mm Does in a UK EWI System
For exposed ground-floor facades, mid-rise residential blocks, and Victorian solid-wall retrofits, Rockwool Frontrock Super 80 mm delivers λ 0.036 W/mK, R 2.22 m²K/W, and a dual-density structure (150 kg/m³ outer face / 80 kg/m³ inner layer) within a single 80 mm thickness. It sits in the broader mineral wool insulation range as the entry thickness in the Super series, supplied 3 slabs per pack covering 1.8 m². The dual-density construction is the defining feature: the hardened outer face takes the adhesive, base coat, and mechanical impact, while the softer back layer moulds to substrate irregularities, removing most shimming work on the masonry it bonds to.
Why Specifiers Choose Rockwool Super 80 mm for UK Walls
- Dual-density impact resistance: The 150 kg/m³ outer face carries compressive stress of ≥ 20 kPa across the full slab, absorbing trolley impact, pedestrian contact, and incidental ground-floor loads without deforming the render substrate.
- A1 reaction-to-fire at every point: Stone wool will not ignite, sustain flame, or generate fuel load — the project fire strategy on relevant buildings typically requires this non-combustible classification across the external wall.
- Substrate-compensating inner face: The 80 kg/m³ back layer moulds to masonry irregularities of up to 10 mm, achieving full adhesive contact on uneven brick or block without extensive preparation rendering.
- Vapour-open construction: With μ ≈ 1, the slab keeps the dew point inside the insulation rather than at the wall interface, protecting solid-wall and period properties from trapped moisture.
- Acoustic uplift on noisy elevations: Dual-density stone wool delivers measurable airborne-noise attenuation, a benefit closed-cell EPS alternatives cannot replicate at the same level.
- Dimensionally stable through UK seasons: Stone wool does not shrink or expand with temperature, so the slab does not feed thermal movement into the base coat at board junctions or reveal returns.
- Recyclable mineral composition: Manufactured from naturally abundant volcanic basalt, supporting BREEAM and circular-economy criteria on regulated projects.
Thermal Specifications — λ, R-Value, Reaction to Fire
| Property | Value | Standard |
|---|---|---|
| Thermal conductivity (λD) | 0.036 W/mK | EN 12667 |
| R-value at 80 mm | 2.22 m²K/W | EN 13162 |
| Reaction to fire | Euroclass A1 | EN 13501-1 |
| Water vapour resistance factor (μ) | ≈ 1 | EN 12086 |
| Specific heat capacity | ≈ 1030 J/kgK | — |
At R 2.22 m²K/W on a single layer, the 80 mm Super slab typically achieves a refurbishment wall U-value in the region of 0.28 W/m²K on a 215 mm dense concrete block substrate — the comparison table further down shows where deeper boards take over for stricter targets.
Physical Specifications — Density, Strength, Dimensions
Physical numbers below set the handling reality on scaffold — pack weight, slab dimensions, and the dual-density distribution together explain why this board behaves differently from single-density alternatives once it is on the wall.
| Property | Value |
|---|---|
| Thickness | 80 mm |
| Slab dimensions | 1000 × 600 mm |
| Density (inner / outer) | 80 / 150 kg/m³ (dual-density) |
| Compressive stress at 10% deformation (CS(10)) | ≥ 20 kPa |
| Tensile strength perpendicular to faces (TR) | ≥ 10 kPa |
| Slabs per pack | 3 |
| Pack coverage | 1.8 m² |
| Pack weight | ≈ 16.2 kg |
| Weight per m² | ≈ 9.0 kg |
Where Rockwool Super 80 mm Performs Best — Wall Types & Exposure
Super 80 mm earns its place where the wall takes mechanical load alongside its thermal duty — ground-floor zones, public-facing elevations, and exposed positions where a softer slab would dent under fixings or impact.
- Ground-floor and street-facing facades: The 150 kg/m³ outer face withstands trolley and pedestrian impact in the lower 2 m of the elevation without leaving dents that would telegraph through the render.
- Mid-rise residential and multi-occupancy buildings: Where current Approved Document B guidance drives non-combustible specification, the A1 rating provides the material-level compliance the building designer needs.
- Pre-1919 solid-wall retrofits: Vapour permeability and the soft inner face suit uneven Victorian brick — see the Victorian solid-wall retrofit guide for whole-elevation detailing context.
- Acoustic-sensitive locations: Properties near major roads, railway lines, or flight paths benefit from the dense fibrous core's airborne-sound absorption.
- Coastal and high-exposure sites: Combined with stainless-steel mechanical fixings, the slab handles wind-load pressures on exposed elevations without long-term degradation.
How Rockwool Super 80 mm Fits Into a Full EWI System
Build-up runs fully vapour-open from substrate to render finish. Bond each slab to prepared masonry with Roker U grey adhesive for mineral wool and EPS, a cementitious formulation specified for stone wool fibres and doubling as the reinforcement base coat. The hardened 150 kg/m³ face receives the adhesive and base coat — branded face outward toward the render — and mechanical fixings from the EWI fixing accessories range apply at a minimum of 8 per m² through 60–90 mm washer plates.
- Adhesive + base coat: Roker U grey (cementitious, vapour-permeable) — same product bonds the slab and reinforces the base layer.
- Reinforcement mesh: Alkali-resistant fibreglass mesh embedded fully in the wet base coat distributes mechanical loads and resists cracking across the slab face.
- Mechanical fixings: 60–90 mm disc washer plugs at 8 per m²; stainless-steel pins for coastal or exposed elevations.
- Render finish: Silicone or silicate topcoats keep the system vapour-open from substrate through to surface, in line with the breathing-wall rationale for mineral wool.
How Rockwool Super 80 mm Compares to Sibling Slabs
| Specification | Super 80 mm (this product) | Super 100 mm | Super 120 mm | Plus 80 mm |
|---|---|---|---|---|
| Range | Frontrock Super | Frontrock Super | Frontrock Super | Frontrock Plus |
| Thickness | 80 mm | 100 mm | 120 mm | 80 mm |
| λ (W/mK) | 0.036 | 0.036 | 0.036 | 0.035 |
| R-value (m²K/W) | 2.22 | 2.78 | 3.33 | 2.29 |
| Density | 80/150 kg/m³ dual | 80/150 kg/m³ dual | 80/150 kg/m³ dual | ≈ 90 kg/m³ |
| Fire rating | A1 | A1 | A1 | A1 |
| Pack coverage | 1.8 m² (3 pcs) | 1.8 m² (3 pcs) | 1.8 m² (3 pcs) | 3.0 m² (5 pcs) |
| Typical use | Exposed/impact-prone elevations | Mid-rise, deeper U-values | Enhanced U-value, deep retrofit | Standard domestic full-wall EWI |
For the full mineral-wool-versus-EPS decision walkthrough, our mineral wool vs polystyrene comparison sets out the trade-offs on cost, U-value per millimetre, and fire performance.
How Rockwool Super 80 mm Performs in UK Weather — Moisture, Frost, Wind Loads
The UK's maritime climate subjects rendered facades to sustained wind-driven rain and cyclic freeze-thaw — conditions the dual-density stone wool is engineered to handle. The factory hydrophobic treatment sheds rain during the installation window, the open-cell fibre structure dries outward rapidly once the render system is on, and dimensional stability across the typical UK service range of −10 °C to +35 °C keeps thermal movement out of the base coat.
On solid-wall retrofits in particular, the μ ≈ 1 vapour resistance keeps the dew-point profile inside the insulation rather than at the brick interface — a known long-term risk where vapour-closed materials are placed externally on traditional masonry. The dual-density structure also reduces wind-uplift sensitivity: the hardened outer face spreads fixing loads better than a uniform-density board, particularly relevant on coastal and upper-storey elevations where wind-load calculations drive fixing density.
Handling and Storage of Rockwool Super 80 mm on UK Sites
- Plan scaffold loading: At ≈ 9 kg/m² and 16.2 kg per pack, Super 80 mm is heavier per square metre than Plus-range alternatives — distribute pack weight across scaffold lifts.
- Cut clean: Use a long-blade insulation knife with the branded face ("THIS SIDE UP") placed downward on a flat board, cutting through the softer back layer first to preserve the hardened outer face.
- Orient correctly: Branded face outward toward the render — installing the slab reversed reduces adhesive bond, fixing performance, and base-coat application quality.
- Store dry: Opaque waterproof sheeting on site; saturated dual-density slabs handle poorly overhead even though the hydrophobic treatment recovers thermal performance after drying.
- Stack flat: Always on a level pallet, away from scaffold edges and protected from mechanical damage to the corners and edges.
Get these five right and the slab arrives at the wall in the same condition it left the pallet — the dual-density structure is at its most forgiving when handled correctly from delivery to fixing.
Pro Tips From UK Installers Using Rockwool Super 80 mm
A few details separate the cleanest dual-density installs from average — the points below come from EWI installers on UK retrofits and new-build elevations across mixed substrates.
- Read the wall before boarding: The 10 mm forgiving range of the soft inner face covers most masonry irregularities, but anything beyond that benefits from a levelling render coat before the slab goes on, not packing behind it.
- Full-bed adhesive on the dense face: Apply Roker U as a full bed to the 150 kg/m³ face — dot-and-dab leaves the slab vulnerable to drumming under impact load, which is the load profile this board exists to handle.
- Set fixings flush with the outer face: Drive washer plates so they sit flush with the hardened face, not recessed into the softer back, keeping the load on the high-density side where it belongs.
- Increase fixing density on exposed elevations: The 8 per m² minimum is a baseline — coastal, high-rise, and wind-funnel positions benefit from project-specific wind-load calculations that often drive density up to 10–12 per m².
Certifications & Compliance — A1, EN 13162, REACH
- EN 13162: Factory-made mineral wool products for buildings — declared λ 0.036 W/mK, dimensional tolerances, and mechanical properties confirmed for the dual-density construction.
- EN 13501-1: Euroclass A1 reaction-to-fire — the highest reaction-to-fire classification, indicating non-combustible material with no contribution to fire at any stage.
- BS EN ISO 9001: Rockwool manufactures under certified quality management (BSI FM 02262), supporting batch-to-batch consistency.
- UK REACH compliant: No hazardous classifications associated with the stone wool composition.
Specifiers routinely cite these certificates as the baseline for non-combustible facade build-ups, and the Building Safety Act 2026 facade-fire briefing sets out where non-combustible classification becomes the specification driver under current Approved Document B guidance.
Is Rockwool Super 80 mm Right for Your Project?
- Choose this slab if: Your project covers exposed ground-floor facades, mid-rise residential blocks, or specifications requiring A1 fire safety paired with enhanced mechanical resistance — the 80/150 kg/m³ dual-density construction delivers impact resilience and a rigid render substrate in one 80 mm board.
- Need a higher R-value in the Super range? The Rockwool Super 100 mm slab shares the same dual-density construction and A1 rating while delivering R 2.78 m²K/W for high-rise specifications and deeper retrofit targets.
- Standard domestic project without impact exposure? The Rockwool Plus 80 mm slab at 90 kg/m³ uniform density and λ 0.035 W/mK delivers R 2.29 m²K/W with larger 3.0 m² pack coverage at a lower price point.
- Low-rise project where fire strategy permits combustible insulation? Browse the graphite EPS board range at λ 0.032 W/mK for higher thermal resistance per millimetre at lower material cost.
All values stated are based on manufacturer-declared data from Rockwool and remain subject to confirmation through project-specific assessment. Specifications may be updated by the manufacturer without prior notice — verify against the current Declaration of Performance before specifying.
What to Order Next — Pack Sizes, Lead Times, Compatible Components
Each pack of Rockwool Super 80 mm covers 1.8 m² (3 slabs at 1000 × 600 mm). For full-system ordering, pair the slab quantity with a matched run of Roker U adhesive, the correct fixing length for substrate plus 80 mm slab depth, and a vapour-permeable render finish from the rendering range.
- Adhesive & base coat: Roker U grey adhesive 25 kg — calculate 4–5 kg/m² bonding plus 3–4 kg/m² for the reinforcement layer.
- Mechanical fixings: Select from the EWI fixing accessories collection matched to total embedment (substrate plus 80 mm slab depth) at a baseline 8 per m².
- Lead time: Full-pack orders confirmed before the daily cut-off ship on the next UK working day.
FAQ — Rockwool Super 80 mm Coverage, Compatibility, Ordering
How many square metres does one pack of Rockwool Super 80 mm cover?
Each pack contains 3 slabs of 1000 × 600 mm and covers 1.8 m² laid flat. Order quantities should include an allowance of 5–10% for cuts at reveals, returns, and junctions, with extra allowance on irregular elevations where multiple board cuts are required.
How does Super 80 mm differ from the Plus 80 mm slab at the same thickness?
The two slabs share thickness and A1 fire classification, but the Super range adds dual-density construction with a 150 kg/m³ outer face for impact resistance, while Plus uses a uniform 90 kg/m³ density. Plus 80 mm has a slightly higher R-value (2.29 vs 2.22 m²K/W) and larger pack coverage (3.0 vs 1.8 m²) at a lower price; Super 80 mm justifies the premium where ground-floor impact, high-rise specification, or substrate compensation is required.
What U-value does 80 mm Rockwool Super typically achieve on a refurbishment wall?
At R 2.22 m²K/W, the 80 mm Super slab typically achieves a refurbishment wall U-value in the region of 0.28 W/m²K on a 215 mm dense concrete block substrate, based on Rockwool's published U-value tables. For wall-by-wall calculation against current Approved Document L guidance, the U-value calculation guide walks through the thickness selection method.
Which adhesive is compatible with dual-density mineral wool?
Use a cementitious adhesive engineered for mineral wool fibres, such as Roker U grey, which bonds the slab to the substrate and serves as the reinforcement base coat in the same product. Polyurethane foam adhesives are not suitable for stone wool because the fibre structure does not provide the closed-cell key the foam needs.
Does Rockwool Super 80 mm meet A1 fire requirements for relevant buildings?
The slab carries Euroclass A1 reaction-to-fire under EN 13501-1 — the highest classification, indicating non-combustible material. Where current Approved Document B guidance requires A1 or A2-s1,d0 insulation in the external wall construction, this product meets the material-level threshold, though the overall system specification remains a project-specific matter for the building designer.
Will the dual-density slab compensate for uneven masonry?
The 80 kg/m³ inner layer moulds gently against substrate irregularities of up to 10 mm, achieving full adhesive contact without shimming or packing behind the board. For walls with greater unevenness, a levelling render coat applied before boarding brings the surface within the slab's compensation range, ensuring a flat, stable plane for the finished facade.
What fixings are recommended for Super 80 mm on exposed elevations?
Use mechanical insulation fixings with 60–90 mm diameter washers at a baseline 8 per m² to spread load across the denser outer face. Stainless-steel pins are recommended for coastal or exposed locations to ensure long-term corrosion resistance. Wind-funnel positions, coastal sites, and high-rise elevations often increase the density to 10–12 per m² following project-specific wind-load calculations.
Technical Documentation — Rockwool Super 80 mm TDS & Datasheets