Twin-Stringer Stairs

Twin-Stringer Undermount Stairs

For added transparency, the single mono stringer is typically replaced with two thin (5/8”) under-mount stringers.

By default, the stringers are placed 6” apart, typically centered on the staircase. For a more dramatic effect, they can be positioned off-center. However, when off-center, long flights may experience excessive twisting, which can be addressed with a few nearly invisible pins securing the stringers to the side wall.

The metal step plates are securely attached to the stringers, and a walking surface board is glued on top.

The walking surface boards are usually ¾” thick hardwood but can also be made from materials like tile or concrete.

To enhance the floating effect, box wood steps can be used. Because box steps are more substantial than the thin stringers, the stringers become less noticeable.