michaelellars.com
Michael Ellars, AIA, APX, CSI, CCCA, CDT, LEED AP, ADAC, CASp
michaelellars.com
Michael Ellars, AIA, APX, CSI, CCCA, CDT, LEED AP, ADAC, CASp
11B-504.2 Treads and risers. All steps on a flight of stairs shall have uniform riser heights and uniform tread depths. Risers shall be 4 inches (102 mm) high minimum and 7 inches (178 mm) high maximum. Treads shall be 11 inches (279 mm) deep minimum.
Exception: Curved stairways with winder treads are permitted at stairs which are not part of a required means of egress.
Added new exception for uniform riser heights and tread depths where a curved stair with winder treads is not part of the means of egress; such stairs are beyond the scope of the 2010 ADA Standards. As part of this change, DSA adopts the (existing) definitions for “means of egress” and “winder.”
11B-505.10 Handrail extensions. Handrail gripping surfaces shall extend beyond and in the same direction of stair flights and ramp runs in accordance with Section 11B-505.10.
Exceptions: … 3. In alterations, where the extension of the handrail in the direction of stair flight or ramp run would create a hazard, the extension of the handrail may be turned 90 degrees from the direction of stair flight or ramp run.
Clarified that Exception 3 applies to stairs as well as ramps consistent with 2010 CBC and logical intent.
A lot of confusion on this one. Here is the old and new language side-by-side:
| Original (2013) | New (2015) |
|---|---|
| 11B-505.10.3 Bottom extension at stairs. At the bottom of a stair flight, handrails shall extend at the slope of the stair flight for a horizontal distance equal to one tread depth beyond the last riser nosing. Such extension shall continue with a horizontal extension or shall be continuous to the handrail of an adjacent stair flight or shall return to a wall, guard, or the walking surface. At the bottom of a stair flight, a horizontal extension of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of the handrail as measured above the stair nosings. Extension shall return to a wall, guard, or the landing surface, or shall be continuous to the handrail of an adjacent stair flight. | 11B-505.10.3 Bottom extension at stairs. At the bottom of a stair flight, handrails shall extend at the slope of the stair flight for a horizontal distance equal to one tread depth beyond the last riser nosing. The horizontal extension of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of the handrail as measured above the stair nosings. Extension shall return to a wall, guard, or the landing surface, or shall be continuous to the handrail of an adjacent stair flight. |
This does not delete the requirement for the extension. Rather, it clarifies that the return is the last part of the extension; the deleted phrase implies that the extension is to return before the horizontal portion, then return a second time.