Description
The deepest board in the graphite façade range: 200 mm carrying a declared thermal resistance of 6.25 m²K/W at λD 0.032 W/mK. Renders World stocks it for solid-wall build-ups where the insulation layer does almost all the work, and where the extra depth changes the detailing around openings more than it changes the fitting.
What the 200mm Graphite Board Does in a Wall Build-Up
Polystyrene EPS Grafit 200mm is a graphite-enhanced expanded polystyrene board declared to EN 13163:2012+A1:2015, fitted as the insulation layer of a render system where a wall build-up needs 6.25 m²K/W from one board. It is the deepest thickness in the graphite EPS insulation boards range.
Depth is the reason to specify it, and depth is also what has to be designed around. At 200 mm the reveals, sills, verges and base of the wall all move outward, so the board belongs to a build-up that has been detailed rather than to a straightforward board-for-board swap.
The manufacturer's technical card declares the board for these uses:
- Walls in external render insulation systems — the declared application this board is stocked for.
- Walls with cladding and a ventilated air gap — the same board behind a rainscreen rather than a render finish.
- Lintels and reveals — declared, though a reveal at this depth is normally formed in a thinner board of the same grade.
- Ring beams as permanent shuttering under render, and soffits within render insulation systems — the two details where continuity of insulation is easiest to design in and easiest to lose.
Declared Thermal and Mechanical Performance
| Property | Declared value | Document and scope |
|---|---|---|
| Declared thermal conductivity (λD) | 0.032 W/mK | EPS 032 Fasada Extra graphite façade board — technical card and declaration of performance |
| Declared thermal resistance (RD) at 200 mm | 6.25 m²K/W | Declared resistance table, 200 mm thickness row, same board |
| Bending strength | ≥ 75 kPa (class BS75) | Same board, declared under EN 13163:2012+A1:2015 |
| Tensile strength perpendicular to faces | ≥ 80 kPa (class TR80) | Same board, declared under EN 13163:2012+A1:2015 |
| Reaction to fire | Class E | Declared for the board under EN 13163:2012+A1:2015 |
| Compressive stress at 10 % deformation | Not declared | Declaration of performance, Bydgoszcz plant |
| Water absorption and water vapour transmission | Not declared | Declaration of performance, Bydgoszcz plant |
Three properties often assumed of a façade board carry no declared value here — compressive strength, water absorption and vapour transmission — which places this board above the damp-proof course, where none of the three is being asked of it. The plinth and below-DPC zone takes a board declared for immersion and loading, and running the graphite board down to meet it at DPC level is the normal detail.
Reaction to fire class E is declared for the board, not for the wall around it. The class of a finished external wall is a property of the whole build-up and comes from the system holder's tested specification and the project fire strategy; where non-combustible insulation is required, mineral wool slabs are the route, and the trade-offs at comparable depths are set out in the graphite EPS and mineral wool facade comparison.
Checking Which Graphite Grade You Are Ordering
Two graphite façade grades from the same manufacturer answer to a board of this description, and they are separate products with separate documents. Every figure above is taken from the stricter of the two, so a calculation built on this page holds whichever grade arrives on site.
The alternative grade, EPS 031 Fasada Extra Plus, declares λD 0.031 W/mK, 6.45 m²K/W at 200 mm, bending strength ≥ 100 kPa and tensile strength ≥ 100 kPa. Dimensional tolerance classes are identical across both grades, so the divergence is confined to conductivity, declared resistance and the two strength classes.
Confirm the grade on the delivery note before a wall build-up calculation is signed off. At 200 mm the declared resistance moves from 6.25 to 6.45 m²K/W between the two grades — 0.20 m²K/W — and declared bending strength moves from 75 to 100 kPa.
Worth knowing how the paperwork behind these figures works: the manufacturer's declaration of performance is issued on the manufacturer's own responsibility under System 3 assessment, with a notified laboratory named for the testing. No product certificate sits behind the values, so the document to request from Renders World is the declaration of performance for the plant that supplied the batch.
Why Specifiers Choose the Deepest Board in the Range
- 6.25 m²K/W in one declared layer — a single board depth with a single declared value, rather than two layers whose combined resistance has to be argued for in a calculation.
- λD 0.032 W/mK from graphite bead chemistry — lower declared conductivity than standard white façade EPS, so the target resistance is reached in less depth than an equivalent white board would need.
- Declared resistance rather than derived resistance — the manufacturer publishes a value per thickness, and that is the figure a calculation should use; dividing thickness by lambda produces a slightly different answer and is not the declared route.
- Thickness tolerance of ± 1 mm at class T1 — the basecoat stays an even thickness across a large elevation instead of chasing steps between boards.
- Unchanged system components — adhesives, basecoats and mesh are the same across the range, so only the plug schedule and the perimeter details move as depth increases.
Board Format and Tolerances, and What They Mean on Site
| Dimension or class | Value | What it means when fitting |
|---|---|---|
| Board format | 1000 × 500 mm | 0.50 m² per board, and a size one person can offer up at height even at this depth |
| Pack | 3 boards, 1.5 m² | A small take-off unit, so quantities land close to the surveyed area |
| Thickness tolerance | T1, ± 1 mm | Even basecoat thickness across the elevation |
| Length and width tolerance | L2 and W2, ± 2 mm | Tight closed joints without packing |
| Squareness | Sb2, ± 2 mm/m | Courses stay square off a level base track |
| Flatness | P5, ± 5 mm | The tolerance to check with a straightedge before rasping |
| Dimensional stability, normal conditions | DS(N)2, ± 0.2 % | Boards hold their size in store |
| Dimensional stability, elevated temperature and humidity | DS(70,-)2, ≤ 2 % | The figure behind the sunlight instruction below |
Flatness at ± 5 mm is the class that decides how much rasping an elevation needs, so a straightedge across the first course before any adhesive is mixed is time well spent. Board size and pack quantity here are the figures published on this product page; the manufacturer's card lists other formats as standard, so the format is confirmed on the order rather than assumed from the card.
How to Install 200mm Boards in an EWI Build-Up
The technical card is specific about sequence and about what may touch the board, and those instructions are what keep a deep build-up performing as calculated. The full layer-by-layer sequence from the base track upwards is mapped in the EWI system build-up guide.
- Bond with an adhesive dedicated to graphite boards. The card permits cement-based adhesives, polyurethane foam adhesives, or water-dispersion bituminous compounds intended for grey graphite boards, each used to its own manufacturer's instructions. Graphite-compatible products sit in the EPS adhesives basecoats range.
- Rasp the face immediately before bonding. Abrading the board directly before it goes on the wall is what the card recommends to lift adhesion of the bedding mortar.
- Leave mechanical fixing until at least 24 hours after bonding. Plug pattern, count and length come from the system holder's schedule against the confirmed board thickness, and the components sit in the insulation fixing accessories range.
- Build the reinforced layer once fixing is complete. Basecoat with fibreglass reinforcing mesh embedded, then the specified finish — the card treats the reinforced layer as a required step over the boards rather than an option.
One prohibition carries real weight on a mixed site: nothing containing organic solvents goes near these boards, which rules out certain sealants, primers and cleaning products sharing the same scaffold lift. Keeping solvent-based products on a separate lift costs nothing to organise and protects every board on the pallet.
How 160mm, 180mm and 200mm Compare
| Board | Declared RD | Choose it when |
|---|---|---|
| 160mm graphite board | 5.00 m²K/W | The calculation is satisfied with 1.25 m²K/W less resistance and reveal depth is tight |
| 180mm graphite board | 5.60 m²K/W | The target sits between what 160 mm and 200 mm deliver |
| 200mm graphite board (this page) | 6.25 m²K/W | The deepest single-layer option in the range is what the calculation asks for |
The step up from 180 mm is worth quantifying before ordering: 6.25 − 5.60 = 0.65 m²K/W for 20 mm of extra depth. All three values come from one declared table in one document, so the boards compare directly without mixing grades — and the depth chosen is decided by the wall build-up calculation, whose method is set out in the U-value and insulation thickness guide.
Is 200mm the Right Depth for the Project?
- Specify it where the calculation needs the deepest single layer available — solid masonry walls contribute little resistance themselves, so the insulation layer carries the wall element.
- Step down to 180 mm where 5.60 m²K/W satisfies the calculation — reveal, sill and verge details all get simpler with 20 mm less depth.
- Specify a different board below the damp-proof course, and mineral wool where the fire strategy requires non-combustible insulation.
No board thickness satisfies a regulation on its own; the build-up does, and the direction of travel for new-build fabric standards is covered in the Future Homes Standard 2026 guide.
Storing and Handling Grey Boards on Site
Graphite boards ask for one discipline that white boards do not, and the card is unambiguous about it. A tarpaulin and five minutes at the end of each lift covers it.
- Shield the boards from direct sunlight, in store and on the wall — the card requires this without qualification because of the steel-grey colour, and the ≤ 2 % dimensional stability class at elevated temperature is the figure behind it.
- Keep them clear of ignition sources and solvent vapours during transport and storage, as the card instructs.
- Protect the edges and corners — on a 200 mm board they are what closes the joints, and they are the first thing a deep board loses in handling.
- Bond boards on the day they are rasped, so the freshly abraded face the card's adhesion recommendation depends on is the one that meets the adhesive.
Ordering, Delivery and What to Pair With the Boards
Take the surveyed wall area in m², divide by the pack area, and add the cutting allowance agreed on the take-off for reveals, soffits and service penetrations. At 1.5 m² per pack, 100 m² of wall gives 100 ÷ 1.5 = 66.7, so 67 packs before that allowance.
Delivery terms are set at store level rather than per product. Renders World processes orders the same day where stock is available, ships pallets on a next working day service or a two business day economy service, and delivers locally by company van from its Southampton base on qualifying orders. All deliveries are kerbside, so a pallet of polystyrene EPS Grafit 200mm boards needs someone on site to move it and somewhere dry to keep it — pallets are wrapped but not weatherproof.
- Adhesive and basecoat — a graphite-compatible product, quantity taken from the adhesive manufacturer's own consumption figure.
- Mesh — reinforcing mesh for the layer over the boards, overlap from the mesh manufacturer's sheet.
- Fixings — plug type and length from the system holder's schedule, ordered against the confirmed board thickness.
- Next step — confirm the grade and compare the full set of thicknesses on the graphite EPS board range page before placing the order.
FAQ — Quantities, Compatibility, Fixings and Fire
How many packs cover a 100 m² elevation?
Sixty-seven, from 100 ÷ 1.5 m² per pack, before the cutting allowance agreed on your take-off. Packs of three keep the over-order small on irregular elevations, which is one advantage of the 1000 × 500 mm format at this depth.
Which adhesives may be used with graphite boards?
Cement-based adhesives, polyurethane foam adhesives and water-dispersion bituminous compounds, in each case a product dedicated to grey graphite boards and used to its own instructions. Anything carrying organic solvents is excluded, and that exclusion covers ancillary products stored beside the boards as well as what goes on the wall.
What plug length suits a 200 mm board?
Plug length is a manufacturer table value read against board thickness, the adhesive bed and the embedment the substrate requires, so it comes from the system holder's fixing schedule rather than from a rule of thumb — and at the deepest board in the range that schedule is worth confirming at design stage. Pattern and spacing work the same way, both covered in the fixing pattern and spacing guide.
Can these boards run below the damp-proof course?
Water absorption and compressive strength are undeclared for this board, so the below-DPC zone is served by a board declared for immersion and loading. Meeting the two at DPC level keeps each board inside the performance its own document declares.
What does class E mean for a rendered wall?
Class E is declared for the board on its own. A rendered external wall is assessed as a complete build-up, so the figure that matters for compliance comes from the system holder's tested specification and the project fire strategy, with mineral wool specified where non-combustible insulation is required.
Technical Documentation