stairway fabricator
An off-site manufacturer of staircases or purpose-made stairway parts, excluding hanging fire escapes.
A stairway supplier is an off-site manufacturer of staircases on or inside a structure, not including hanging fire escapes. This role does not apply when stairways are built entirely on-site, although they may be assembled from delivered parts if those materials are constructed specifically as stairway pieces.
Off-site manufacture can produce a complete staircase or components made specifically for a staircase. Assembly at the building therefore does not by itself exclude a stairway fabricated in delivered sections.
The distinction is between manufacturing stairway pieces and supplying ordinary materials from which a stairway is built entirely on site. A general supplier of structural wood or steel is not necessarily the fabricator of the staircase made from those materials.