Our stair stringers range from 117 treads (steps) and are made for standard 'rise' and 'going' and work on a 1000mm max distance between the centers of the stringers The rise is the vertical measurement taken from one step level to the nextStandard rise is 175mm The going is the horizontal measurement taken from the front of one step to the nextOutdoor stairs are viewed as potentially more hazardous because of rain and snow A riser higher than 7 inches is not recommended outside, though interior stair dimensions can be higher than that The ratio for exterior stairs is two risers the tread = 26 inches The optimum riser for exterior stairs is 6 1/2 inches, making the tread 13Bilco Cellar Door Stair Stringer Size E x 3525 x 9 Galvanized Steel Stair Stringer 3 Tread Model# SZ ESS (3) $ 159 64 Bilco Cellar Door Stair Stringer Size SL x 4425 x 9 Galvanized Steel Stair Stringer 4 Tread Model# SZ SLSS $ 168 77 3Step Ground Contact Pressure Treated Pine Stair Stringer
Staircase Dimensions