Stairs string
A stair string, stringer, or stringer board, is the panel on either side of a flight of stairs to which the treads and risers are fixed.
The string is described as ‘closed’ if it conceals the profile of the treads and risers. It is described as ‘open’ or ‘cut’, if its upper edge is cut away so that the profile of the treads and risers is visible from the site.
A 'routed string' has slots cut into it, into which the treads and risers can be fixed.
A string that is fixed to the wall is described as the 'wall string'.
The perpendicular distance between the pitch of the stairs and the top of the string, is described as the 'string margin'.
Wheelchair platform stairlifts travel along the stair string, allowing wheelchair users to travel up and down stairs while remaining seated in their wheelchair.
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