A stringer is the primary load-bearing diagonal beam of a staircase. In rough framing, stringers are typically cut from dimensional lumber with a sawtooth pattern to support the treads and risers directly on top. They dictate the rise and run of the entire stair system and must be laid out with precise geometry.
Heard on the job
I'm using the framing square and stair gauges to lay out the cuts on this outside stringer.
Insider tip
Always cut and test-fit one stringer perfectly, then use it as a template to trace the remaining stringers for the staircase.
Also heard as
- stair stringer
- carriage
Do not mix it up with
- String: A stringer is typically the structural, notched support underneath, whereas a string is often the finished, routed side board.