I'm designing a stairs in a very tight space that has an upper landing and a lower landing, each segment requires a 90 deg turn. If the landing riser heights are different from the main run – does this present a hazard? If so – why?
Presently the upper landing is 10.5" drop, followed by steps of ~9.5", and back to 10.5" on the lower. The stair runs are 11.5"
Best Answer
Code says risers can’t be more than 8” high and can’t vary from the largest to smallest by more than 3/8”. (See IRC R311.7.5.)
Treads can’t be less than 9” and can’t vary by more than 3/8”.