Description
Rockwool Frontrock Super 160 mm is the thickest slab in our dual-density Super range — a Euroclass A1 stone wool board engineered for near-zero U-value targets and deep-retrofit specifications, supplied 2 slabs per pack covering 1.2 m². At this thickness the slab earns its place where the project demands maximum non-combustible insulation depth in a single layer, avoiding the double-boarding complexity that thinner alternatives would require.
What Rockwool Super 160 mm Does in a UK EWI System
Near-zero U-value targets on taller buildings and deep-retrofit projects, paired with Euroclass A1 fire classification across the external wall, present the specification problem the thickest slab in our Frontrock Super range is built to solve — λ 0.036 W/mK and R 4.44 m²K/W in a single 160 mm board from the mineral wool insulation range. It is the maximum single-layer thermal depth available in the dual-density Super series, supplied 2 slabs per pack covering 1.2 m². The 160 mm profile reaches whole-wall U-values in the region of 0.15 W/m²K on steel-frame new build and 0.19–0.20 W/m²K on refurbishment substrates without resorting to double-layer boarding or the interlayer thermal-bridge risk that double-boarding introduces.
Why Specifiers Choose Rockwool Super 160 mm for UK Walls
- Highest R-value in a single Super slab: R 4.44 m²K/W in one board removes the staggered-joint double-boarding process and eliminates the interlayer thermal bridges that two thinner layers can create.
- A1 fire classification at full depth: Non-combustible stone wool maintains the highest reaction-to-fire rating across the entire 160 mm profile — current Approved Document B guidance typically drives this material-level threshold on relevant buildings.
- Dual-density mechanical resilience: The 150 kg/m³ hardened outer face carries compressive stress of ≥ 20 kPa, providing a rigid render substrate even at maximum thickness where uniform-density boards would feel softer underfoot.
- Deep substrate compensation: The 80 kg/m³ inner layer moulds to masonry irregularities of up to 10 mm — the additional depth provides a more forgiving profile when bonding to uneven pre-1919 solid brick.
- Vapour-open across the full thickness: μ ≈ 1 maintained through 160 mm of stone wool keeps the dew-point profile inside the insulation even in the most challenging UK winter conditions — a key safety margin over vapour-closed alternatives at equivalent depths.
- Specification-grade thermal target: Suited to retrofit programmes targeting ambitious U-value figures and to new-build elevations specified against the Future Homes Standard 2026 fabric-performance brief.
- Recyclable mineral composition: Manufactured from naturally abundant volcanic basalt, supporting BREEAM and lifecycle-carbon assessments 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 160 mm | 4.44 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 | — |
R 4.44 m²K/W is the deepest single-layer thermal resistance available in the Super range — for projects where the U-value calculation requires still more, double-layer boarding with staggered joints becomes the next specification step.
Physical Specifications — Density, Strength, Dimensions
Physical numbers below set the handling reality on scaffold — pack coverage drops to 1.2 m² at this thickness, so storage volume per square metre of facade rises significantly compared with the 80–120 mm Super variants.
| Property | Value |
|---|---|
| Thickness | 160 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 | 2 |
| Pack coverage | 1.2 m² |
| Pack weight | ≈ 16.2 kg |
| Weight per slab | ≈ 8.1 kg |
Where Rockwool Super 160 mm Performs Best — Buildings & Wall Types
The 160 mm Super slab is the specification thickness for projects where the U-value brief is ambitious, the fire strategy is non-negotiable, and single-layer simplicity is preferred to double-boarding — the combination that defines deep-retrofit and near-zero new-build EWI work in the UK.
- Near-zero and Future Homes Standard 2026 specifications: Provides the deepest single-layer stone wool option for projects aligned with the Future Homes Standard 2026 fabric-performance brief, where wall U-values typically sit in the 0.15–0.18 W/m²K range.
- Solid-wall deep retrofit: Maximum thermal upgrade on pre-1919 brick and stone properties without compromising vapour openness, particularly relevant where the retrofit programme targets ambitious post-installation U-value figures.
- Taller buildings with stringent thermal targets: Combines the A1 fire classification typically required on relevant buildings under current Approved Document B guidance with deep thermal resistance in one specification choice.
- Grant-funded retrofit programmes: Public-sector and Warm Homes Plan-style schemes targeting hard-to-treat solid-wall housing benefit from maximum thermal benefit per installation visit, reducing return-visit risk on the funded works.
- Passive House-adjacent designs: Reaches the upper boundary of the Passive House wall U-value range on steel-frame construction (~0.15 W/m²K), with double-boarding available where lower figures are required.
How Rockwool Super 160 mm Fits Into a Full EWI System
At 160 mm depth, system integration requires deliberate attention to fixing length, base-track sizing, and reveal detailing — standard components specified for 80–100 mm boards will not carry over. Bond each slab to prepared masonry with Roker U grey adhesive for mineral wool and EPS, applying a full perimeter-and-centre-spot pattern on the hardened 150 kg/m³ face — branded "THIS SIDE UP" marking outward toward the render. Mechanical fixings from the EWI fixing accessories range apply at a minimum 8 per m² with shaft length sized to clear the full 160 mm board depth plus the required substrate embedment.
- Adhesive + base coat: Roker U grey (cementitious, vapour-permeable) — same product bonds the slab and reinforces the base layer with embedded fibreglass mesh.
- Mechanical fixings: 60–90 mm disc washer plugs at 8 per m² baseline; shaft length must achieve 25–40 mm minimum embedment beyond the 160 mm board, which typically means shafts of 200 mm or longer depending on substrate.
- Base track: Specify a 163 mm-profile base track to support the full insulation depth at the wall base, maintaining level alignment and protecting the lower edge from ground-level moisture and impact.
- Reinforcement mesh: Alkali-resistant fibreglass mesh embedded fully in the wet Roker U base coat distributes mechanical loads and resists cracking across the slab face.
- 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 160 mm Compares to Sibling Slabs
| Specification | Super 80 mm | Super 100 mm | Super 120 mm | Super 160 mm (this product) |
|---|---|---|---|---|
| Range | Frontrock Super | Frontrock Super | Frontrock Super | Frontrock Super |
| Thickness | 80 mm | 100 mm | 120 mm | 160 mm |
| λ (W/mK) | 0.036 | 0.036 | 0.036 | 0.036 |
| R-value (m²K/W) | 2.22 | 2.78 | 3.33 | 4.44 |
| Density | 80/150 kg/m³ dual | 80/150 kg/m³ dual | 80/150 kg/m³ dual | 80/150 kg/m³ dual |
| Fire rating | A1 | A1 | A1 | A1 |
| Pack coverage | 1.8 m² (3 pcs) | 1.8 m² (3 pcs) | 1.8 m² (3 pcs) | 1.2 m² (2 pcs) |
| Typical use | Entry exposed/impact | Mid-rise, multi-occupancy | Deep retrofit, enhanced U-values | Maximum performance, near-zero targets |
For the full mineral-wool-versus-EPS decision walkthrough at maximum thickness, our mineral wool vs polystyrene comparison sets out the trade-offs on cost, U-value per millimetre, and fire performance.
How Rockwool Super 160 mm Performs in UK Weather — Moisture, Frost, Wind Loads
The UK's net-zero direction and the tightening of Building Regulations fabric-performance standards place increasing emphasis on deep wall U-values — and 160 mm of vapour-permeable A1 stone wool sits at the top end of single-layer thermal performance in that direction. The 160 mm profile keeps the dew-point profile safely inside the insulation through prolonged UK winter conditions, a critical advantage over vapour-closed alternatives at equivalent depths where condensation risk grows with thickness.
Dimensional stability across the typical UK service range of −10 °C to +35 °C prevents the thermal-expansion movement that thicker uniform-density boards can transmit into the render. On exposed and coastal upper-storey elevations, the dual-density structure spreads fixing loads better than a uniform board would at this thickness — particularly important since wind-load demands rise both with building height and with overall insulation depth. The Building Safety Act 2026 facade-fire briefing sets out where the A1 classification becomes the specification driver under current Approved Document B guidance on relevant buildings.
Handling and Storage of Rockwool Super 160 mm on UK Sites
- Plan scaffold storage volume: At 1.2 m² per pack, the 160 mm slab takes substantially more scaffold volume per square metre of facade than Plus-range alternatives — stage deliveries to match boarding tempo rather than bulk-storing on the deck.
- Confirm fixing shaft length before ordering: Standard plugs for 80–100 mm boards will not reach the substrate behind a 160 mm slab — specify 200 mm or longer shafts to achieve the 25–40 mm minimum embedment.
- Cut clean with a long blade: Use a 200 mm or longer insulation knife with the branded face ("THIS SIDE UP") placed downward on a stable flat surface, slicing through the softer back layer first to preserve the hardened outer face.
- Position deliberately on scaffold: Each slab weighs ≈ 8.1 kg individually — manageable by hand, but the 160 mm depth makes one-handed positioning more awkward than thinner variants, particularly when working at reach over reveal returns.
- Store dry: Opaque waterproof cover on site; saturated packs handle poorly even though the hydrophobic treatment recovers thermal performance after drying.
Get these five right and the slab arrives at the wall in the same condition it left the pallet — particularly relevant on deep-retrofit programmes where pack count per square metre of facade is the highest in the mineral wool range.
Pro Tips From UK Installers Using Rockwool Super 160 mm
A few details separate the cleanest deep-retrofit installs from average — the points below come from EWI installers working on solid-wall and Future Homes Standard projects across the UK.
- Order base track and fixings in the same call: A 160 mm slab needs a 163 mm-profile base track and long-shaft fixings — order them with the slabs themselves rather than discovering a mismatch on site mid-installation.
- Confirm reveal geometry before boarding the main wall: At 160 mm projection, reveal slabs may sit proud of standard window frames — check reveal depth at survey stage and plan the slab-to-frame relationship before the main board run starts.
- Full-bed adhesive on the dense face: At 160 mm the slab's mass amplifies the consequences of poor adhesive contact — apply Roker U as a full bed to the 150 kg/m³ face rather than dot-and-dab.
- Increase fixing density per wind-load calculation: 8 per m² is the baseline; deep-retrofit elevations and mid-rise positions routinely move to 10–12 per m² following project-specific wind-load assessment at this thickness.
- Plan delivery cadence carefully: 1.2 m² per pack means roughly 50% more packs per square metre of facade than the 1.8 m² Super variants — coordinate delivery with scaffold-loading capacity to keep landings clear.
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 across production runs.
- UK REACH compliant: No hazardous classifications associated with the stone wool composition; Rockwool fibres are not classified as possible human carcinogen.
Specifiers routinely cite these certificates as the baseline for non-combustible facade build-ups at maximum thickness — the material-level threshold the building designer needs before assembling a project-specific system specification.
Is Rockwool Super 160 mm Right for Your Project?
- Choose this slab if: Your project demands the maximum single-layer thermal resistance available in the Frontrock Super range — near-zero specifications, Future Homes Standard fabric-performance targets, deep retrofit on solid-wall stock, or taller buildings where non-combustible insulation at maximum depth is specified.
- Can the U-value target be reached with less depth? The Rockwool Super 120 mm slab at R 3.33 m²K/W provides strong thermal performance with larger 1.8 m² pack coverage, easier handling, and lower material cost where the calculation allows it.
- Standard high-rise specification? The Rockwool Super 100 mm slab at R 2.78 m²K/W remains the specification-grade choice for mid-rise residential and multi-occupancy buildings where 100 mm satisfies the U-value brief.
- Entry-level dual-density coverage? The Rockwool Super 80 mm slab at R 2.22 m²K/W suits projects where the additional thickness is not justified by the U-value or fire-strategy brief.
- Low-rise where fire strategy permits combustible insulation? Browse the graphite EPS board range at λ 0.032 W/mK for equivalent thermal resistance at thinner profile and 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 160 mm covers 1.2 m² (2 slabs at 1000 × 600 mm). For full-system ordering at this thickness, the slab quantity must be paired with thickness-appropriate base track, long-shaft mechanical fixings, and a matched run of Roker U adhesive — components designed for thinner boards will not carry over directly to 160 mm specification.
- Adhesive & base coat: Roker U grey adhesive 25 kg — calculate 4–5 kg/m² bonding plus 3–4 kg/m² for the reinforcement layer.
- Long-shaft mechanical fixings: Select from the EWI fixing accessories collection at 200 mm-plus shaft length to achieve 25–40 mm substrate embedment beyond the 160 mm board, at a baseline 8 per m² adjusted upward for wind-load on mid-rise and exposed elevations.
- Base track: Specify a 163 mm-profile base track from the fixing accessories range to support the full insulation depth at the wall base.
- Lead time: Full-pack orders confirmed before the daily cut-off ship on the next UK working day.
FAQ — Rockwool Super 160 mm Coverage, Compatibility, Ordering
How many square metres does one pack of Rockwool Super 160 mm cover?
Each pack contains 2 slabs of 1000 × 600 mm and covers 1.2 m² laid flat. On deep-retrofit programmes, order with 5–10% allowance for cuts at reveals, returns, and parapet detailing, and plan deliveries against scaffold-loading capacity — pack count per square metre of facade is roughly 50% higher than the 1.8 m² Super variants.
What U-value does 160 mm Rockwool Super typically achieve?
On a steel-frame new-build wall, 160 mm of Frontrock Super typically achieves a wall U-value in the region of 0.15 W/m²K — at the upper boundary of the Passive House target range. On a 215 mm dense block refurbishment substrate, the result is typically 0.19–0.20 W/m²K, subject to project-specific calculation. The U-value calculation guide walks through the thickness selection method against current Approved Document L guidance.
Do I need special fixings for 160 mm boards?
Standard-length plugs designed for 80–100 mm boards will not reach the substrate behind a 160 mm slab. Select shafts long enough to pass through the full board plus 25–40 mm minimum embedment into the masonry — typically 200 mm or longer. Large-diameter washers (60–90 mm disc) and stainless-steel pins are recommended at a baseline 8 per m², adjusted upward per project-specific wind-load calculation.
Can 160 mm mineral wool reach Passive House U-value targets?
Passive House wall specifications typically target U-values in the region of 0.10–0.15 W/m²K. The 160 mm Super slab at R 4.44 m²K/W reaches approximately 0.15 W/m²K on steel-frame new build — the upper boundary of that target zone. On solid-wall refurbishment the result typically sits at 0.19–0.20 W/m²K. Where the design requires a lower figure, double-layer boarding with staggered joints is the next specification step.
Does Rockwool Super 160 mm meet A1 requirements for relevant buildings?
The slab carries Euroclass A1 reaction-to-fire under EN 13501-1 — the highest classification, indicating non-combustible material across the full 160 mm depth. Where current Approved Document B guidance requires A1 or A2-s1,d0 insulation in the external wall construction of relevant buildings, this product meets the material-level threshold; the overall system specification remains a project-specific matter for the building designer.
Is 160 mm worth the cost increase over 120 mm for the same wall?
The 160 mm slab carries a higher per-square-metre material cost and smaller pack coverage than 120 mm. Where the U-value calculation confirms 120 mm achieves the required target, stepping down saves cost and improves handling. Where 160 mm is genuinely needed — near-zero, Future Homes Standard alignment, or maximum retrofit depth — the single-layer approach avoids the labour of double-boarding and removes the interlayer thermal-bridge risk that two stacked slabs introduce.
Is 160 mm mineral wool a sustainable specification at this thickness?
The slab is manufactured from naturally abundant volcanic basalt with no blowing agents carrying ozone-depleting or global-warming potential, and off-cuts can be returned to Rockwool's recycling programme. The additional embodied material at 160 mm is offset within the first few years of service by the lifetime energy savings from deep U-value reduction — a balance that supports BREEAM and lifecycle-carbon assessments.
Technical Documentation — Rockwool Super 160 mm TDS & Datasheets