Code excerpt regarding technical requirements for protruding objects: general, protrusion limits, post-mounted objects, vertical clearance, and required clear width.
11B-307 Protruding objects
11B-307.1 General. Protruding objects shall comply with Section 11B-303.
Animal containment areas shall not be required to comply with Section 11B-303.
Areas of sport activity shall not be required to comply with Section 11B-303.
11B-307.2 Protrusion limits. Objects with leading edges more than 27 inches (686 mm) and not more than 80 inches (2032 mm) above the finish floor or ground surface shall protrude 4 inches (102 mm) maximum horizontally into the circulation path.
Exception: Handrails shall be permitted to protrude 4 1/2 inches (114 mm) maximum.
Advisory 11B-307.2 Protrusion limits. When a cane is used and the element is in the detectable range, it gives a person sufficient time to detect the element with the cane before there is body contact. Elements located on circulation paths, including operable elements, must comply with requirements for protruding objects. For example, awnings and their supporting structures cannot reduce the minimum required vertical clearance. Similarly, casement windows, when open, cannot encroach more than 4 inches (100 mm) into circulation paths above 27 inches (685 mm).
11B-307.3 Post-mounted objects. Free-standing objects mounted on posts or pylons shall overhang circulation paths 12 inches (305 mm) maximum when located 27 inches (686 mm) minimum and 80 inches (2032 mm) maximum above the finish floor or ground. Where a sign or other obstruction is mounted between posts or pylons and the clear distance between the posts or pylons is greater than 12 inches (305 mm), the lowest edge of such sign or obstruction shall be 27 inches (686 mm) maximum or 80 inches (2032 mm) minimum above finish floor or ground.
Exception: The sloping portions of handrails serving stairs and ramps shall not be required to comply with Section 11B-307.3.
This exception only applies to the sloping portion of handrails including the sloping portion of handrail extensions; the level portions of handrail extensions must comply with Section 11B-307.3!
11B-307.3.1 Edges and corners. Where signs or other objects are mounted on posts or pylons, and their bottom edges are less than 80 inches (2032 mm) above the floor or ground surface, the edges of such signs and objects shall be rounded or eased and the corners shall have a minimum radius of 1/8 inch (3.2 mm).
11B-307.4 Vertical clearance. Vertical clearance shall be 80 inches (2032 mm) high minimum. Guardrails or other barriers shall be provided where the vertical clearance is less than 80 inches (2032 mm) high. The leading edge of such guardrail or barrier shall be located 27 inches (686 mm) maximum above the finish floor or ground.
Exception: Door closers and door stops shall be permitted to be 78 inches (1981 mm) minimum above the finish floor or ground.
11B-307.4.1 Guy braces. Where a guy support is used within either the width of a circulation path or 24 inches (610 mm) maximum outside of a circulation path, a vertical guy brace, sidewalk guy or similar device shall be used to prevent a hazard or an overhead obstruction.
11B-307.5 Required clear width. Protruding objects shall not reduce the clear width required for accessible routes.
Protruding objects may not reduce the required clear width of an accessible route, which includes a number of circulation components such as maneuvering clearances at doors. Thus, where a protruding object occurs at or “within” an accessible clear space component, the accessible clear space component must shift clear of the protruding object. Protruding objects are not allowed to encroach onto any component of the accessible route; the route must shift clear of the object.