The Complete Guide to Metal Stringer Staircases

Metal stringer staircases — where a pair of steel beams carry the treads with nothing else visible underneath — have become the defining statement of contemporary residential design. But the engineering behind them is more nuanced than the minimal aesthetic suggests.

The key structural consideration is deflection. A stringer must be stiff enough that the staircase does not bounce or flex under load — a common complaint on cheaper installations. At RiseOnStairs, we design our stringers with a minimum depth-to-span ratio of 1:20, and we always engineer for dynamic loads, not just static ones.

Finish options have expanded dramatically in recent years. Powder coating gives you any RAL colour with excellent chip resistance. Raw steel with a clear lacquer gives an industrial warmth that gets better with age. And sandblasted hot-rolled steel, sealed with a penetrating oil, is currently our most requested finish.

The tread material you pair with your stringer changes the entire character of the piece. Solid oak gives warmth and tradition. Glass treads make the whole structure appear to float. Concrete treads work beautifully in raw, industrial-influenced interiors.