Placner — the ribbed steel sheathing
A 0.3 mm galvanised sheet doing three jobs at once: it braces the panel, it keys the sprayed insulation, and it closes the wall.
Specification
Cold-rolled galvanised steel sheet with V-form ribs. Base sheet 0.3 mm, zinc coating Z200 (200 g/m²), panel 600 × 2,500 mm (1.5 m²). The 5 mm on the drawing is the overall profiled depth including rib height, not the sheet gauge.
Function 1 — bracing
Screwed to the external stud flange, it provides in-plane racking resistance to the panel. That is a structural contribution, not a finish.
Function 2 — mechanical key
The rib profile anchors the sprayed INSULTERM 600 across the full wall face. A flat board cannot do this, which is why the layer sits where it does.
Function 3 — vapour behaviour
At 0.3 mm, galvanised steel is effectively vapour-impermeable. In subtropical and Mediterranean climates this is not a concern. For continental heating climates, hygrothermal analysis to EN ISO 13788 / EN 15026 is required before specification — an assessment of how moisture moves through the build-up over a year — and Solid System will supply it on request.
Corrosion
Z200 gives approximately 14 µm of zinc per face. Z275 is available in the same profile and is specified as standard for coastal and marine-exposed sites.
Flexibility
The sheet is malleable and adapts to curved and irregular geometry, which is a design freedom a rigid board does not offer.