ETICS installation step by step: the Class Mat Therm PSE system

1. Prepare the substrate

The substrate must be sound, dry, clean and load-bearing, free from dust, grease, laitance and loose parts. Significant flatness defects are corrected before installation. Inspection and preparation of the substrate follow the Cahier du CSTB 3035_V4 referred to in the DTA.

2. Fix the base track

• Mark the start of the system horizontally; aluminium base track 15 cm above ground.
• Fixings every 30 cm maximum, no more than 5 cm from the end of the track.
• Leave a 3 mm gap between two tracks; mitre-cut at corners.
• Choose the track to match the insulation thickness (4 to 30 cm).

3. Mix the adhesive and bond the boards

Mix with an electric mixer, leave to stand for 5 minutes; pot life 2 to 3 hours. Manual application in dabs or beads (perimeter bead and dabs), or full-surface bonding on a flat substrate.

Bond the boards horizontally from one corner of the wall to the other, vertical joints staggered by at least 25 cm, and check flatness with a 2.5 to 3 m aluminium straightedge. At window and door corners, cut the boards in an L shape.

Grey EPS: full-surface bonding, or dabs or beads with immediate anchoring (before the adhesive sets), 2 anchors per board; protect the boards from the sun during storage and installation.

Open joints between boards: under 5 mm → polyurethane foam (about 1 hour to expand and harden); 5 to 10 mm → EPS strips. The foam must not fill significant gaps in the insulation.

The adhesive needs at least 24 hours of drying before any further work, depending on the weather.

4. Anchor

• At least 3 anchors per 1200 × 600 mm board in the main area (4.2 per m²); more at detail points and edges depending on wind exposure, without exceeding the maximum in the DTA tables.
• Minimum distance of 10 cm from the edge of the board.
• TermoZ CS II 8: drill Ø 8 mm, effective anchorage depth 25 mm, flush or countersunk installation.
• Length: insulation thickness + 10 mm of adhesive + any existing render + 25 mm, then the next TermoZ length up (see anchor length).

5. Corners and stops

• PVC mesh corner bead: embedded in the fresh base coat on external corners, the mesh fully covered before the finish.
• Top stop profile: chosen for the insulation thickness (4 to 20 cm), fixed through its perforated side; its drip edge protects the top edge of the ETICS.
• Render stop profile: aligned and pressed into the fresh embedding mortar, for a clean stop between two finishes.

6. Reinforced base coat

1. First pass of Cm’Armatflex, about 2.0 kg/m² of powder, with a 6 mm notched stainless-steel trowel.
2. Embed the glass-fibre mesh (160 g/m²) with a stainless-steel smoothing trowel, from top to bottom, with at least 10 cm of overlap; the mesh must be fully embedded, in the middle of the base coat.
3. After at least 24 hours of drying, second pass of about 2.0 kg/m² with a stainless-steel trowel.
4. Minimum dry thickness of the reinforced base coat: 3.0 mm. Wait at least 24 hours before the next step.

7. Primer and finish

Apply the Fixat Pro Universal primer (required, 0.2 kg/m², roller or brush), let it dry for 24 hours, then the chosen finishing render: spread with a stainless-steel trowel to the grain size and textured with a plastic float. Choosing the finish is covered in choosing a finishing render.

Weather conditions

• Adhesive mortars and base coat: apply between +5 °C and +25 °C.
• No risk of frost within 24 hours of applying the adhesive, base coat or finish.
• In cold and damp weather, each layer can take several days to dry.
• Quantities come from the calculator; waiting times are summed up in the FAQ.