Shared Deck Stairs Wear Out on a Different Clock
A back deck carries one household. A walk-up stair in a six-unit building carries every trip anyone in that building makes, plus deliveries, plus everything being hauled up and down on moving day. The wear turns up in the same places every time: tread nosings worn round, stringer notches splitting at the back of the cut, fasteners working loose at the landing connection, and a handrail gripped so often that the finish is gone and the mounting has gone soft. On a private deck those are maintenance items you get to a season late. On a shared stair they are the thing everyone in the building touches twice a day. That changes the spec: heavier stringers, more bearing at the landings, and hardware sized for the traffic rather than just for the span.

