Stainless steel wall panels:
the sheet is standard,
the substrate is not

We make metal wall panels in 1220 x 2440 standard sheet, or cut to the elevation. The standard size exists because the mill stocks it: stainless steel wall panels 4x8 is the size the mills stock; anything else is a cut, and a cut is a line on the quote.

Stainless steel wall panels are quoted on the flat area plus the folds, never on the elevation area. That single sentence explains most of the price differences between two quotes for the same wall: one is pricing the sheet, the other is pricing the sheet plus every return plus the material lost in the corner.

Stainless wall panels cost more per square metre than coated aluminium and cannot delaminate. If the brief is a coloured wall in a dry interior, aluminium is the cheaper correct answer and we will say so. If the brief is a wall that gets cleaned with solvent, or one where a scratch must not show a different colour underneath, stainless is the answer.

The practical limits

• 1500 × 3500 mm is the largest single flat face. Above that a wall becomes a run of panels, with joints, whether the drawing shows them or not.
• 0.8 mm is the thinnest we will supply for a wall. Below that the sheet telegraphs every imperfection in the substrate.
• 1.5 mm is where the sheet stops needing a full carrier and starts being self-supporting over short spans.

Metal wall panels interior work is judged on the joint line, not on the sheet. A dead-flat panel on a wall that is 8 mm out of plumb over three metres will show a shadow gap that closes and opens — and the gap is the only feature on the wall.

Metal interior wall panels over stud need a 12 mm ply carrier or the joint will telegraph. That is not a preference: a stud at 400 mm centres behind a 1.0 mm skin is a series of ridges, and every one of them will read in raking light.

Interior steel wall panels are usually 0.8 or 1.0 mm; 1.2 mm only where something will hit them. The thickness has almost nothing to do with appearance and everything to do with what the wall is asked to survive — a trolley, a door handle, a chair back.

What we ask for before quoting

• The substrate: concrete, stud, or timber, and whether it is already built
• The flatness you can achieve, in mm over 2 m, not "good"
• The joint you want, in mm, and whether it is a shadow gap or a tight seam
• Whether a single panel will ever need to come out

Flat metal wall panels show every ripple; folded ones hide it in the shadow line. A return on four sides turns a sheet into a tray, and a tray resists oil-canning in a way a flat sheet cannot — for the price of four folds.

Metallic wall panels in the trade usually means a coated aluminium sheet, not stainless. Worth knowing when you are comparing quotes: a metre rate for metallic wall panels and a metre rate for stainless steel wall panels are not the same product, and the word "metallic" is doing a lot of work.

Surface, and what it hides

Metallic wall panels interior finishes scratch white; a matte grain hides it better. On a brushed or bead-blasted face a scratch reads as a change in grain direction — visible up close, invisible from a metre. On a mirror or a coated metallic finish the same scratch removes the colour and reads white.

Exterior, and the one rule

A metal panel for wall use outdoors needs a drained cavity behind it. Not sealed — drained. Water gets behind any skin eventually; the only question is whether it has a path out. A 25 mm ventilated cavity, open top and bottom, is the minimum, and it is the detail that gets deleted first when a budget is cut.

One stainless steel wall panel is replaceable if it was numbered and its fixing is accessible. Two conditions, both cheap at the drawing stage and both impossible afterwards.

Every stainless wall panel is drawn at 1:5 before cutting, including the return. The drawing is what makes the panel a known object: its number, its position, its fixing, and which way its grain runs.

A stainless steel panel for wall fixing is drilled on the bench, never on site. A hole drilled on site goes through the finish, leaves a burr on the face, and puts swarf where it will rust — on a surface the client has already approved.

Interior sheet metal wall panels for a lift lobby should come out panel by panel. A lift lobby is the highest-traffic wall in the building and the one where a damaged panel is most likely; if the run has to come down to replace one sheet, it never gets replaced.

Two patterns, one rule

Decorative metal wall panels are the same sheet with a pattern rolled, etched or punched into it. A decorative metal wall panel pattern repeats on the sheet, so the panel width follows the repeat — you cannot cut a repeating pattern wherever you like and keep it centred.