The strings are the diagonal components into which the treads and risers are housed. On this type the edges are parallel, the balustrade is fitted on top using spindles of the same height.
In this case the strings are cut to the profile of the treads and risers. On traditional stairs the spindles are held in by a return nosing, on contemporary ones they fit directly into the tread and are of different heights.
The strings can be closed or cut, the riser is omitted. To comply with Building Regulations the gap can be closed with a half riser, glass, dowel or metal rod.
The strings can be closed or cut, curved on plan a geometrical stair does not have the same angle throughout the flight. The strings on a helical stair are usually parallel around a helix.
The treads are shaped like a paddle, the going is measured over 2 steps making the pitch is steeper. Can only be used in a loft conversion when space is not available for a conventional stair.
This type of stair is used when the stair will be clad with another material for example pre- finished flooring. It can be a closed or a cut string as shown. Due to movement in timber we do not recommend using ceramics.