Continuous Handrail and symetrical switch back stairs

[lunatick]

Question on continuous hand rails in switch back stair.

Typically in this scenario? a) the stair is symmetrical (equal number of stair adjoining flights) b)the interior handrail wraps around from flight to flight.

Atypical switch back condition. a) stair is asymetrical, with one flight containing 3 treads and the other 11. b) design called for the interior hand rail to be discontinuous and to terminate on each floor between the 11 tread flight and the 3 tread flight.

AHJ wants the interior rail to be continuous.

I am not finding this in IBC. What am I missing?

 

[cda]

what edition

I think some of the rules changed in the 09

 

[mark handler]

International Building Code

[ 2012 (Second Printing) ]

1012.4 Continuity.

Handrail gripping surfaces shall be continuous, without interruption by newel posts or other obstructions.

Exceptions:

1. Handrails within dwelling units are permitted to be interrupted by a newel post at a turn or landing.

2. Within a dwelling unit, the use of a volute, turnout, starting easing or starting newel is allowed over the lowest tread.

3. Handrail brackets or balusters attached to the bottom surface of the handrail that do not project horizontally beyond the sides of the handrail within 11/2 inches (38 mm) of the bottom of the handrail shall not be considered obstructions. For each 1/2 inch (12.7 mm) of additional handrail perimeter dimension above 4 inches (102 mm), the vertical clearance dimension of 11/2 inches (38 mm) shall be permitted to be reduced by 1/8 inch (3 mm).

4. Where handrails are provided along walking surfaces with slopes not steeper than 1:20, the bottoms of the handrail gripping surfaces shall be permitted to be obstructed along their entire length where they are integral to crash rails or bumper guards.

 

[lunatick]

CDA - 2009, but like to know of 2012 also.

Mark. my interpretation of this comment concerns itself with continuity within the flight or ramp. Not between flights or ramps, except where you are wrapping the railing due to accessibility extension requirements.

Otherwise, would this continuation not also occur on the exterior wall and be interrupted by the doors, etc.

Again, dealing with an asymmetrical switch back stair.

 

[jeharrarch]

2009 IBC "1012.6 Handrail extensions. Handrails shall return to a wall, guard or the walking surface or shall be continuous to the handrail of an adjacent stair flight or ramp run. Where handrails are not continuous between flights, the handrails shall extend horizontally at least 12 inches..." If the inboard handrail is not continuous through the switchback, it would have to meet the extension requirements for a "regular" handrail - a horizontal extension of 12" beyond the last riser. Making the rail continuous between flights allows you to avoid having a 12" obstruction (the handrail) when you turn the corner to continue along the stairway. If you have enough room for the extension, though, the inboard handrail need not be continuous if it is returned to the wall, floor, etc.

 

[Paul Sweet]

I think it depends where the stairs start & stop. If you walk up 3 treads, then in a straight line for 3 ft. (a landing) or more before turning to go up the 11 treads, then I don't think a continuous handrail would be of any benefit. If you walk up the 3 treads and turn right away to go up the 11 treads, then the rail would have to be continuous.