Description
At λD 0.031 W/mK the 180 mm graphite board delivers RD 5.80 m²K/W, dropping typical UK masonry walls to 0.15–0.17 W/m²K and reaching the Passive House wall fabric threshold on well-pointed brickwork, the near-Passive depth specified to EN 13163 for Energiesprong, net-zero new-build, and Social Housing Decarbonisation Fund band A pathways.
What EPS Grafit 180 mm Does in a UK EWI System
At RD 5.80 m²K/W from λD 0.031 W/mK, EPS Grafit 180 mm is a graphite-enhanced expanded polystyrene insulation board that brings standard 215 mm brick walls to 0.15–0.17 W/m²K, the near-Passive thickness within the graphite EPS insulation board range. Certified to EN 13163, it serves as the primary insulation layer in high-performance EWI build-ups on Passive House, Energiesprong, and net-zero projects up to 18 m in height.
Specifiers reach for 180 mm when the project targets Passive House pre-certification, net-zero operational carbon, or band A retrofit. The 0.65 m²K/W gain over the 160 mm board crosses from deep-renovation performance into certified Passive territory on well-pointed brickwork, and that step decides whether the wall element passes on its own merits.
Why Specifiers Choose EPS Grafit 180 mm for UK Walls
- Passive House wall threshold on well-pointed brickwork — assembly U-value lands at 0.15–0.17 W/m²K on standard 215 mm solid brick, subject to calculation, touching the ≤ 0.15 W/m²K target where brick conductivity is at the lower end of the range.
- RD 5.80 m²K/W from 180 mm depth — graphite bead chemistry matches roughly 225 mm of white EPS, saving over 45 mm of total build-up depth and protecting architectural proportions on net-zero elevations.
- Energiesprong-compatible performance — the consistent λD 0.031 W/mK across the production range underpins reliable U-value calculations at scale for guaranteed-performance retrofit contracts.
- Band A retrofit enabler — combined with high-performance glazing, loft insulation, and MVHR, the 180 mm wall element delivers the fabric performance behind the most ambitious band D-to-A upgrade pathways.
- Self-supporting rigidity at depth — BS100 bending strength keeps the board flat when leant against the wall face, with no bowing during the adhesive cure window.
- Standardised across the Renders World EWI range — bonds with the same adhesives, basecoats, and meshes as thinner variants; only the fixing plug steps up to the LTX 220 mm, the longest in the standard LTX range.
- Dispatched from the Renders World Southampton warehouse — pallet quantities for Passive House and net-zero programmes are typically shipped next working day on consolidated EWI deliveries.
Thermal Specifications — λ, U-Value, Reaction to Fire
| Property | Value |
|---|---|
| Declared thermal conductivity (λD) | 0.031 W/mK |
| Thermal resistance (RD) at 180 mm | 5.80 m²K/W |
| Indicative wall U-value (215 mm solid brick + 180 mm) | 0.15–0.17 W/m²K, subject to calculation |
| Reaction to fire (EN 13501-1) | Euroclass E |
| Classification string | EPS EN 13163 T1-L2-W2-Sb2-P5-BS100-DS(N)2-TR100 |
Under current Approved Document B guidance, Euroclass E EPS is permitted within EWI build-ups on residential buildings below 18 m where the project fire strategy specifies horizontal mineral wool fire barriers at each floor level and around openings. For buildings above 18 m, or where the fire strategy requires non-combustible insulation throughout, specify from the mineral wool insulation range; the trade-offs at enhanced thicknesses are set out in the graphite EPS vs mineral wool facade guide.
Physical Specifications — Density, Strength, Dimensions
| Property | Value |
|---|---|
| Range | Genderka EPS 031 Fasada Extra Plus |
| Thickness | 180 mm |
| Board size | 1000 mm × 500 mm |
| Coverage per board | 0.50 m² |
| Boards per pack | 3 |
| Pack coverage | 1.5 m² |
| Density | 15 kg/m³ |
| Bending strength | ≥ 100 kPa (BS100) |
| Tensile strength perpendicular to faces | ≥ 100 kPa (TR100) |
| Standard | EN 13163:2012+A1:2015 |
Where EPS Grafit 180 mm Performs Best — Wall Types and Build-Up
The 180 mm board is the near-Passive thickness for projects where wall-element performance must cross from deep-renovation into certified Passive House territory. Three project types account for most UK use at this depth, and each leans on the additional resistance for a different reason.
Passive House New-Build and Pre-Certification
Projects pursuing Passive House certification use 180 mm of graphite EPS as the external wall layer, delivering 0.15–0.17 W/m²K on standard 215 mm brick. On well-pointed brickwork with conductivity at the lower end of the range, the wall element alone reaches the ≤ 0.15 W/m²K fabric target without supplementary internal insulation, simplifying the build sequence and protecting room sizes.
Energiesprong Whole-House Retrofit
UK Energiesprong programmes specifying factory-precision EWI panels favour 180 mm for its blend of substantial R-value and consistent declared λ across the production range. Reliable thermal characteristics underpin the guaranteed-performance contracts that define this model, where calculated U-values must match measured post-installation performance within tight margins.
Net-Zero Carbon New-Build
Architects designing to net-zero operational carbon reach for 180 mm to push the heating-demand contribution from external walls to the lowest practical level. The resulting wall U-value frees the dwelling emission rate calculation from compensating heavily through services, allowing simpler MVHR and heat-pump sizing.
How EPS Grafit 180 mm Fits Into a Full EWI System
Boards bond to the prepared substrate with a circumferential-and-spot adhesive bead from the EPS adhesives and basecoats range, aiming for a minimum 40 % contact area to satisfy wind-load design under BS EN 1991-1-4. At 180 mm depth, full-face support is critical: maintain a continuous perimeter bead at least 30 mm wide plus three central spots to prevent voids that could allow deflection under negative wind pressure on exposed elevations.
After a minimum 24-hour adhesive cure, secure with 6–8 mechanical fixings per m² from the insulation fixing accessories range. The matched plug for 180 mm boards on standard masonry is the LTX 220 mm polystyrene fixing plug, the longest in the standard LTX range, giving 30–40 mm of embedment beyond the board and adhesive. This plug ships in 100-piece packs rather than the 200-piece packs used for shorter variants, so adjust ordering quantities. Rasp the outer face for a basecoat key, apply reinforcing basecoat with embedded mesh, then finish with the specified render. The full layer-by-layer sequence is mapped in the EWI system build-up layers explained guide.
How EPS Grafit 180 mm Compares to Sibling EPS Boards
| Variant | Key Spec | When to Choose |
|---|---|---|
| 160 mm Grafit | RD 5.15 m²K/W · LTX 200 mm plug | PAS 2035 band A deep renovation |
| 180 mm Grafit (this board) | RD 5.80 m²K/W · LTX 220 mm plug | Near-Passive, Energiesprong, net-zero |
| 200 mm Grafit | RD 6.45 m²K/W · LTX 220 mm plug | Certified Passive House, max depth |
Choose 180 mm when the project targets Passive House pre-certification, net-zero design, or Energiesprong-style guaranteed-performance retrofit. Step down to 160 mm for PAS 2035 band A deep renovation without the Passive House wall threshold; step up to 200 mm when the wall U-value must clear 0.15 W/m²K independently regardless of brick conductivity. The calculation method behind these bands sits in the U-value calculation and wall insulation thickness guide.
How EPS Grafit 180 mm Performs in UK Weather — Moisture, Frost, Wind Loads
Graphite EPS has a closed-cell structure with very low water absorption (W2 under EN 13163), so the board maintains declared thermal performance through the wet UK heating season when installed within a correctly detailed render system. Freeze-thaw cycling does not degrade the bead structure, and typical UK winter temperatures leave the material unaffected.
Wind-load resistance at 180 mm depends substantially on the combined adhesive and mechanical fixing specification rather than the board itself. On standard exposure zones the recommended 6–8 plugs per m², with full-perimeter adhesive contact, delivers reliable retention to BS EN 1991-1-4 design pressures. On exposed coastal or upland sites, increase fixing density to 8–10 per m² and verify with the structural engineer, because the LTX 220 mm shank transmits considerably more lever-arm force to the substrate than shorter plugs. Condensation behaviour on solid-wall retrofits at enhanced depths is covered in the dew point and condensation risk guide.
Handling and Storage on Site
At 180 mm and 15 kg/m³ density each board weighs roughly 1.35 kg, comfortable for single-handed positioning at scaffold height. At this depth the bulk of each pack and the heat-absorbing graphite face both demand more disciplined handling than standard retrofit thicknesses, so the workflow adjustments below pay back across a Passive House or net-zero programme.
- Widen scaffold platforms to 900 mm — standard 600 mm boards leave limited working space once a 180 mm board is propped against the wall. A 900 mm platform gives comfortable room for adhesive application and fixing operations.
- Pre-stage full packs per lift in fixing sequence — packs occupy substantial platform footprint at this depth, so staging from the base track upward minimises repositioning at height.
- Rasp and adhere within the same working window — the freshly rasped surface provides the strongest bond, so it is a step worth timing well rather than preparing a full day's allocation in advance.
- Use a depth stop on the drill at 220 mm plug length — consistent embedment across the facade is a step worth getting right; verify the first few fixings of each elevation, and account for the 100-piece pack size when calculating quantities.
Certifications and Compliance — BBA, EN, Reaction to Fire
- EN 13163:2012+A1:2015 — harmonised European standard for factory-made EPS, covering declared thermal conductivity, dimensional tolerances, and mechanical strength.
- Reaction to fire — Euroclass E (EN 13501-1) — suitable for EWI systems on residential buildings below 18 m where the project fire strategy specifies horizontal fire barriers at each floor level, under current Approved Document B guidance.
- CE marking and Declaration of Performance — every pack supports Building Control evidence packs, PAS 2035 retrofit coordinator records, and SAP assessor documentation.
- Passive House and net-zero contribution — at RD 5.80 m²K/W the board typically delivers wall U-values of 0.15–0.17 W/m²K on 215 mm solid brick, subject to calculation, approaching the ≤ 0.15 W/m²K wall target used in Passive House energy-balance modelling and exceeding all current Approved Document L thresholds. The wider trajectory is set out in the Future Homes Standard 2026 guide.
Is EPS Grafit 180 mm Right for Your Project?
- Best fit: Passive House pre-certification, Energiesprong whole-house retrofit, net-zero new-build, or band A pathway on standard masonry constructions.
- Deep-renovation alternative: PAS 2035 band A targets without the Passive House wall threshold favour the 160 mm Grafit board at marginally reduced material cost.
- Maximum-depth alternative: certified Passive House projects requiring a definitive ≤ 0.15 W/m²K wall element on any brick type step up to the 200 mm Grafit board at RD 6.45 m²K/W.
- Fire-strategy alternative: buildings above 18 m, or projects requiring non-combustible insulation throughout, specify from the mineral wool insulation range.
- Trade desk: Passive House designers and Energiesprong delivery partners can request consolidated take-off sheets and phased deliveries before the first pallet leaves the Renders World warehouse.
What to Order Next — Pack Sizes, Lead Times, Compatible Components
Confirm the surveyed wall area in m², divide by 1.5 m² per pack, and add 5–10 % for cutting waste around reveals, soffits, and service penetrations. Pair each pallet with sufficient adhesive and basecoat from the adhesives and basecoats range (typically 4–5 kg/m² for the adhesive and 4 kg/m² for the basecoat), plus the LTX 220 mm fixing plug at 6–8 fixings per m². The LTX 220 mm ships in 100-piece packs, so a 100 m² facade at 7 fixings per m² needs 7 packs rather than the 4 needed for shorter-plug 200-piece packs.
For Passive House designers, Energiesprong delivery partners, and net-zero programme managers, Renders World provides consolidated take-off sheets, per-m² pricing, and split deliveries phased to scaffold rotation on request via the trade desk.
FAQ — EPS Grafit 180 mm Thickness, Coverage, Installation
How many packs does a typical detached Passive House new-build require?
A three-bedroom detached new-build with roughly 100–120 m² of external wall (after deducting openings) needs around 70–85 packs of 3 boards, including 5–10 % for cutting waste. Smaller semi-detached or terraced projects scale proportionally against the measured survey, and the trade desk supports phased delivery where on-site storage is limited.
Does 180 mm achieve the Passive House wall U-value target?
On a typical 215 mm solid brick wall, 180 mm of graphite EPS brings the assembly to approximately 0.15–0.17 W/m²K. On well-pointed brickwork with lower conductivity (around 0.70 W/mK or below), the board reaches the ≤ 0.15 W/m²K target on the wall element alone. On higher-conductivity brick the assembly sits marginally above 0.15 W/m²K, which energy-balance modelling typically accommodates when offset by high-performance glazing, airtightness, and MVHR. For a definitive independent pass regardless of brick type, the 200 mm board provides the additional margin.
Which fixing plug pairs with the 180 mm board on standard masonry?
The LTX 220 mm plug, the longest in the standard LTX range, is the correct match for a 180 mm board on brick or block, providing 30–40 mm of embedment beyond the board and adhesive. It ships in 100-piece packs rather than the 200-piece packs used for shorter variants, so factor the pack size into ordering. Install 6–8 fixings per m² and use a depth stop on the drill for consistent embedment.
When is 180 mm worth specifying over 160 mm?
The additional 20 mm adds 0.65 m²K/W and shifts the wall U-value from approximately 0.17–0.19 W/m²K down to 0.15–0.17 W/m²K. For Passive House pre-certification, Energiesprong contracts, or net-zero new-build, this margin moves the wall element from deep-renovation into certified Passive territory on well-pointed brickwork. For band A targets without Passive House ambition, the 160 mm board delivers the required performance at marginally lower material cost.
What is the expected service life within an EWI render system?
Within a correctly detailed render system with intact basecoat and finish, graphite EPS maintains declared thermal performance throughout the EWI system's typical 30+ year design life. Periodic visual inspection and prompt repair of any render breaches preserves long-term performance.
Is the 180 mm board suitable for buildings above 18 m?
For residential buildings above 18 m, current Approved Document B guidance and Building Safety Act provisions typically call for non-combustible insulation throughout the facade. Specify from the mineral wool insulation range for these projects, subject to the project fire strategy.
Technical Documentation — EPS Grafit 180 mm TDS, DoP, Certificates