Commercial stair tread & risers

QuestionEdit

What are the minimum and maximum allowances on both tread length and riser height?

AnswerEdit

Yes there are a bunch of regs about about stairs. 10 inch minimum for the tread and 7-3/4 max height for the riser. Max difference on risers is 3/8 inch. Minimum head room is 6'8", minimum landing is 36 inch. Doors may not swing out over landing unless it's a screen door. Handrail required at min. 34 inches and it must have a "gripable" profile and return to the wall or building at both ends. No open ends to snag clothes and trip someone.