External wall insulation (ETICS) in Luxembourg: the Class Mat Therm PSE system
Class Mat Therm PSE is an external thermal insulation composite system (ETICS) on expanded polystyrene, for masonry or concrete walls, in new build and renovation. It is a system under ETA-25/0619, also assessed in France by DTA 7/26-1828_V1 (French technical approval), and classed B-s1, d0 for reaction to fire in the DTA configurations. This guide sums up how it is built, how to choose the insulation and what to check for a project in Luxembourg.
How is the system built?
Seven layers, each with its Class’Mat products. Every product has a technical data sheet in the documentation.
| Layer | Role | Products |
|---|---|---|
| 0 — Profiles | Base and stops of the system | Aluminium base track, top stop profile, render stop profile |
| 1 — Bonding | Fixing the boards to the wall | Cm’EPS fix, Cm’Stirofix, Cm’Armatflex |
| 2 — Insulation | Thermal resistance | White EPS, Grey EPS |
| 3 — Fixing | Mechanical fixing of the boards | TermoZ CS II 8 screw-in anchors |
| 4 — Reinforced base coat | Reinforced base layer | Cm’Armatflex, glass-fibre mesh, corner beads |
| 5 — Primer | Preparing for the finish | Fixat Pro Universal |
| 6 — Finish | Protection and appearance of the façade | Cm’AcryTop, Cm’SilikatTop, Cm’SiliTop, Cm’Granitplast |
Which insulation and which thickness?
Two 1200 × 600 mm boards are available: White EPS, λD 0.038 W/(m·K), and graphite Grey EPS, λD 0.031 W/(m·K). At the same thickness, grey gives a higher thermal resistance.
The DTA requires a thermal calculation for each project, using the resistance R certified by ACERMI for the chosen thickness. Extract from the ACERMI tables:
| Thickness | R White EPS (m²·K/W) | R Grey EPS (m²·K/W) |
|---|---|---|
| 100 mm | 2.60 | 3.20 |
| 120 mm | 3.15 | 3.85 |
| 140 mm | 3.70 | 4.50 |
| 160 mm | 4.20 | 5.15 |
| 200 mm | 5.25 | 6.45 |
| 240 mm | 6.30 | 7.70 |
Where measures against fire spread on the façade are required, the DTA limits the thickness to 200 mm for the solution it describes. See also White or Grey EPS.
Which certificates?
- ETA-25/0619: European Technical Assessment of the system.
- DTA 7/26-1828_V1: French technical approval, valid until 30 September 2032, scope mainland France.
- ACERMI: certificates 12/150/777 (White EPS) and 15/150/1045 (Grey EPS).
- Reaction to fire of the system: B-s1, d0 in the DTA configurations with all four finishes; the board alone is Euroclass E.
- TermoZ CS II 8 anchors: ETA-14/0372.
Details: ETA, DTA and ACERMI and the B-s1, d0 class.
On which walls?
The DTA covers flat vertical walls of masonry or concrete, in new build or renovation, as well as the renovation of an existing ETICS (over-insulation) within the applicable fire-safety rules. The substrate must be sound, dry, clean and load-bearing; significant flatness defects are corrected before installation. See substrates.
In Luxembourg: what to check
The DTA is a French approval: for a project in Luxembourg, the system’s European reference is ETA-25/0619. For each building, check the applicable requirements (thermal, fire safety, municipal procedures).
Energy-renovation subsidies (the Klimabonus scheme) are described on guichet.lu; their conditions and amounts change, so check the official page before starting a project.
Documents, calculator and support
- The calculator gives the quantity of each product from the area, thickness and finish.
- The documentation gathers the DTA, the ACERMI certificates and the technical data sheets, as a ZIP per layer.
- For installation: ETICS installation steps. For the finish: choosing a finishing render.
- A question about a project? Contact us.