The MLN Metal Lamella Firebreak Fixing is a hammer-driven steel fastener for securing mineral wool lamella and slab boards in external wall insulation (EWI/ETICS) systems. Manufactured in galvanised steel (MLN) with an optional stainless-steel MLN-A2 variant for enhanced corrosion resistance, the fixing comprises a rigid metal pin and a wide support washer to distribute load and resist wind suction. Classified to A1 reaction to fire (EN 13501-1), it is suitable as a firebreak fixing within mineral wool systems.

Suitable Insulation Boards

Compatible Substrates (ETA Categories A, B, C & E)

If the substrate condition is uncertain, carry out a pull-out test to confirm suitability.

Key Features

• Hammer-driven 8 mm metal core for robust anchorage in mineral wool systems.
• Wide support washer spreads load and limits localised compression of lamella boards.
• A1 reaction to fire — ideal for firebreak zones and high-rise applications (per EN 13501-1).
• Available in galvanised steel (MLN) and stainless steel (MLN-A2) for aggressive environments.
• Designed to transfer wind suction loads as an additional mechanical fixing.
• National Technical Assessment: ITB-KOT-2021/1815 (ed.1).

Sizes & Box Quantities

Stainless-steel MLN-A2 (110, 140, 170 mm) available to order — contact us to place your order.

Application

Preparation

• Mark out the fixing grid to suit the system design and wind-load zone.
• Check for hidden services (cables/pipework) before drilling.
• Select the correct drilling mode for the substrate (rotary for AAC/hollow units; hammer for dense masonry).

Installation steps

1. Apply adhesive to mineral wool boards per the EWI specification and place boards tightly with staggered joints.
2. Drill perpendicular through the board into the substrate; clean dust from the hole.
3. Insert the fixing body so the washer contacts the insulation surface.
4. Hammer in the metal pin until fully seated and the washer sits flush; do not over-drive or dish the surface.
5. Install the specified number of fixings per board, increasing density at corners, openings and high-load areas.
6. Proceed with basecoat and reinforcement mesh as per system design.

Fixing pattern & density

• Follow the project design. For mineral wool façades, typical guidance is:
  • Up to 15 m height: minimum 8 pcs/m² (field) and 10 pcs/m² (corner zones).
  • Above 15 m height: minimum 10 pcs/m² (field) and 12 pcs/m² (corner zones).
• Maintain consistent edge distances; avoid placing fixings too close to edges or through board joints unless specified.

Quality checks

• Carry out pull-out tests where substrate variability is suspected.
• Replace any fixing that spins or fails to grip; re-drill if necessary.