Glossary: Stair Stringer
A **Stair Stringer** is the structural member (typically cut from 2x12 lumber) that runs diagonally along the side of a staircase, supporting the treads and risers.
Stair Framing Specifications
Stringers must be cut accurately to maintain uniform step heights. Under IRC R311.7.5, the variation between the greatest riser height and the smallest riser height within any flight of stairs must not exceed 3/8 inches (9.5 mm) to prevent tripping hazards.