Perforated metal panels

What it is

Perforated metal is sheet or plate in which a pattern of holes has been punched or cut, leaving a flat, rigid panel that lets light, air, sound and liquids through while acting as a screen, guard or surface. The hole shape, size, pitch and arrangement together set the open area – the percentage of the sheet that is hole – and the panel's look, strength and acoustic behaviour.

Perforated panels are used on facades and sunscreens, plant and service screens, balustrade and fence infill, ceilings and acoustic linings, signage, stair and walkway edge panels, machine guards and ventilation grilles. Where weight and cost per square metre matter more than a flat face, expanded metal or aluminium expanded mesh may be the better choice.

Types and options

Panels can be supplied flat, with folded return edges for stiffness, with welded studs or brackets, or set in frames as handrail infill or screen panels. Plain margins are left at edges and fold lines so panels can be bent and fixed without tearing through a row of holes.

Design and compliance

Perforation reduces the stiffness and strength of the sheet roughly in proportion to the open area, so thickness, fold depth and fixing spacing are chosen together. Facade and screen panels are designed for wind to AS/NZS 1170.2, ASCE 7 or EN 1991-1-4; balustrade infill for the infill loads of AS/NZS 1170.1, ASCE 7 or EN 1991-1-1; and opening sizes in barriers must meet the climbing and sphere rules of the local code, such as the 125 mm sphere rule of NCC 2022 or the 4 in sphere of the IBC. Panels used as machine guards follow EN ISO 13857, AS 4024.1 or OSHA 1910.212 for reach distances.

For acoustic linings, the perforated face works with an absorbent backing behind it; sound absorption is a property of the tested system (ISO 354 or ASTM C423), not of the sheet alone. Hole patterns are often described by the codification of ISO 7806 or the dimensions of DIN 24041. Facade fire rules apply to the coating and build-up as for any cladding – see cladding systems.

Fabrication and finishing at World Steel

Perforated sheet stock is produced by specialist perforators on multi-tool presses and supplied by World Steel with the project package; custom and image patterns are punched or laser-cut from the DXF file to the architect's design. In the World Steel plant we cut, fold and drill panels, weld brackets, studs and frames using qualified procedures under ISO 3834-2 and our AS/NZS 5131 and EN 1090-2 systems, and check flatness and edge margins against the shop drawings.

Mild steel panels and frames are hot-dip galvanised by qualified galvanisers – thin sheets are reviewed for distortion first – or painted to the specification. Architectural panels are powder-coated or, in aluminium, anodised by specialist finishers. Panels are interleaved and crated by elevation for export shipping.

Selecting and specifying

• Choose the hole shape, size, pitch and open area for the purpose – light, airflow, view, acoustics or a graphic – and request a sample.
• State material, thickness, panel sizes, margins, fold details and fixing method.
• Give wind or barrier loads and the code for openings where panels form a balustrade.
• Name the finish standard and colour; for image perforation, supply the artwork or DXF.