Max. Riser Height For Deck on Commercial Building?

[fj80]

2015 IBC. What's the maximum riser height allowed for steps on a deck on the side of an existing commercial building? Steps will go from edge of deck down to ground.

We want to create wide treads (about 18" wide) so that people can sit on them almost like bleachers.

Does it fall under Section 1011.5.2 for stairways, or anywhere else since it's outside the building?

 

[RLGA]

Risers must be 4 to 7 inches in height.

Regarding treads, I think you're confusing width with depth. The depth of a tread can be any length but can be no shorter than 11 inches. The width would be based on the required egress capacity but not less than 35 inches if the 9-inch maximum projection is used based on a minimum width for stairs of 44 inches (unless a 36-inch-wide stair is permitted).

 

[fj80]

Risers must be 4 to 7 inches in height.

Regarding treads, I think you're confusing width with depth. The depth of a tread can be any length but can be no shorter than 11 inches. The width would be based on the required egress capacity but not less than 35 inches if the 9-inch maximum projection is used based on a minimum width for stairs of 44 inches (unless a 36-inch-wide stair is permitted).

Yeah, I meant depth. But riser height is the question.

 

[ADAguy]

If intended to be used for seating the seat height should be 17 (18" if 3 risers) - 19" with steps (with 6" [4" min.]- 6.33" risers) provided alongside depending on the width of the deck. This would sort of be like a bleacher (no?) if so you must also allow for WC locations.

 

[steveray]

Does the building allow a wood deck?