A
External walls of residential and public buildings
Cast-in-place and masonry external walls where the insulation layer is limited in thickness and energy calculations are demanding
Product 02 · Graphite XPS
What graphite does
Graphite powder is added during production of the board. While the good fire performance of conventional XPS board is maintained, a high-elasticity, high-strength lightweight protective layer forms on the surfaces of the interconnected walls of the foam cell structure.
This layer lowers the thermal transmittance of the product and at the same time increases board strength and dimensional stability. For the same thermal resistance the insulation layer can therefore be thinner, or at the same thickness it gives better thermal performance, which suits external wall and roof projects with high energy-saving standards and limited space for insulation.
- Excellent thermal insulation, with a thermal transmittance below that of standard XPS board.
- Superior fire performance, supplied in class B1 or B2 as the project requires.
- A lightweight protective layer forms on the cell walls, raising board strength and dimensional stability.
- The silver-grey colour makes it easy to tell apart from standard XPS board on site.
0.026Typical thermal transmittance W/(m·K)
Technical Data
Technical data
| Test item | Unit | Typical value / range |
|---|---|---|
| Thermal conductivity | W/(m·K) | 0.026–0.028 |
| Density (apparent) | kg/m³ | 32–45 |
| Compressive strength (at 10% deformation) | kPa | 200–500 |
| Water absorption (by volume) | % | ≤1.5 |
| Dimensional stability (70 °C, 48 h) | % | ≤1.5 |
| Fire performance class | — | B1 / B2 |
| Common thicknesses | mm | 30 / 40 / 50 / 60 / 80 |
| Standard sizes | mm | 1200×600 / 1800×600 |
Company product literature states that the thermal conductivity of graphite XPS board can reach the order of 0.020 W/(m·K); the table above lists the common supply and test ranges, and the factory inspection report for the batch concerned is decisive.
Comparison
Choosing between graphite and standard XPS board
| Item | Standard XPS board | Graphite XPS board |
|---|---|---|
| Thermal conductivity | ≈0.028 | 0.026–0.028 |
| Thickness needed for the same thermal resistance | Baseline | Thinner |
| Board colour | Light yellow-green / blue | Silver-grey (with graphite) |
| Dimensional stability | Good | Better |
| Typical use | Ordinary external walls, roofs, underfloor heating, floors | External walls with high energy-saving standards, positions where insulation thickness is limited |
| Identification on site | Delivery paperwork needed | Told apart directly by colour, convenient for acceptance |
Note: adding graphite powder changes how the board absorbs light, so the surface of outdoor stacks heats up more than that of natural-colour boards; covered storage is recommended on site.
Applications
Suitable positions of use
B
Roofs and inverted roofs
Concrete roof insulation layers that need low water absorption and high compressive strength
C
Prefabricated and sandwich elements
Factory-made elements with insulation core material embedded inside, cut to size
Back to the XPS insulation board technical data page Quotations and samples