Results 1 to 7 of 7
  1. #1
    Ben Liu's Avatar
    Ben Liu Guest

    Default maximum gap between stairs and wall

    Does anyone know if the building code stipulates a maximum gap between the edge of a stairway or landing and an adjacent wall or doorway? See the attachment. This is an exterior stairway for a commercial building (mixed 'B' and 'M' occupancy) in southern California. The treads and landings are concrete; the supporting frame is steel.

    The only reference I could find in the 2007 CBC is in section 1009.5.1, which states that stairway treads and landings shall have a solid surface except in Group F, H and S occupancies, where "openings in treads and landings shall not be prohibited provided a sphere with a diameter of 1.125 inches cannot pass through the opening". In this particular case, the treads and landings are in fact solid except for the gap between the edge and the wall.

    Similar Threads:
    Attached Files Attached Files
    OREP Insurance

  2. #2
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: maximum gap between stairs and wall

    Quote Originally Posted by Ben Liu View Post
    The only reference I could find in the 2007 CBC is in section 1009.5.1, which states that stairway treads and landings shall have a solid surface except in Group F, H and S occupancies, where "openings in treads and landings shall not be prohibited provided a sphere with a diameter of 1.125 inches cannot pass through the opening". In this particular case, the treads and landings are in fact solid except for the gap between the edge and the wall.

    Actually, this is what that section states: (underlining and bold are mine)
    - 1009.5.1 Stairway walking surface. The walking surface of treads and landings of a stairway shall not be sloped steeper than one unit vertical in 48 units horizontal (2-percent slope) in any direction. Stairway treads and landings shall have a solid surface. Finish floor surfaces shall be securely attached.
    - - Exception: In Group F, H and S occupancies, other than areas of parking structures accessible to the public, openings in treads and landings shall not be prohibited provided a sphere with a diameter of 1.125 inches (29 mm) cannot pass through the opening.

    The exception is only in regards to the "shall have a solid surface" and is only applicable to Group F, H, and S occupancies and not in parking structures accessible to the public.

    So there are several ways to look at it:
    a) If that is an F, H, or S occupancy and not in parking structure accessible to the public, then the there may be openings in the walking surface up to 1.125 inches.
    b) If that is not an F, H, or S occupancy or is in a parking structure accessible to the public in those occupancies, then the there may NOT be openings in the walking surface.

    Another section to consider as a way to look at it:
    - SECTION 1013
    - - GUARDS
    - - - 1013.1 Where required. Guards shall be located along open-sided walking surfaces, mezzanines, industrial equipment platforms, stairways, ramps and landings that are located more than 30 inches (762 mm) above the floor or grade below. Guards shall be adequate in strength and attachment in accordance with Section 1607.7. Where glass is used to provide a guard or as a portion of the guard system, the guard shall also comply with Section 2407. Guards shall also be located along glazed sides of stairways, ramps and landings that are located more than 30 inches (762 mm) above the floor or grade below where the glazing provided does not meet the strength and attachment requirements in Section 1607.7.
    - - - - Exception: Guards are not required for the following locations:
    - - - - - 1. On the loading side of loading docks or piers.
    - - - - - 2. On the audience side of stages and raised platforms, including steps leading up to the stage and raised platforms.
    - - - - - 3. On raised stage and platform floor areas, such as runways, ramps and side stages used for entertainment or presentations.
    - - - - - 4. At vertical openings in the performance area of stages and platforms.
    - - - - - 5. At elevated walking surfaces appurtenant to stages and platforms for access to and utilization of special lighting or equipment.
    - - - - - 6. Along vehicle service pits not accessible to the public.
    - - - - - 7. In assembly seating where guards in accordance with Section 1025.14 are permitted and provided.

    c) The "open sides" of that stair are where the treads and landing stop. That is the place where the guard is supposed to be.

    I have run across installation like that several times and, if you try to address that space as the 4" opening in guards you will very quickly realize that ones foot will also very quickly go through that 4" open space and get stuck just as quickly, leading to a very painful fall down the stairs.

    While the application of the 1.125 inch opening would solve this issue, this opening allowance is only in very specific occupancies, and not even allowed in those occupancies parking garage which are accessible to the public.

    All of which means this part applies: Stairway treads and landings shall have a solid surface.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  3. #3
    Join Date
    Mar 2007
    Location
    Houston, Texas
    Posts
    294

    Default Re: maximum gap between stairs and wall

    I do not recall ever seeing any code defined permitted gap for that particular circumstance. I suspect it has been designed with a gap to try and keep some isolation between the stairwell assembly and the main structure. If that is in fact the case then the local code authority will have to pass judgement on the design.

    As I see it though that gap would have to be considered "part of" the walking surface since it is available "underfoot" and the exceptions to code do not seem to apply in this case.

    Is this by chance part of an emergency fire escape system or is it intended for the day to day use by the building occupants?


  4. #4
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: maximum gap between stairs and wall

    Quote Originally Posted by Phillip Stojanik View Post
    As I see it though that gap would have to be considered "part of" the walking surface since it is available "underfoot"

    That's the problem ... it is *not* available "underfoot" any more than walking off the edge of the tread or landing is, and those areas are required to be protected with guards.

    I know what you are trying to say, but I had the same problem trying to explain why "holes/slots" in the walking surface would be allowed for everyday use (even when for restricted use the maximum open dimension is not very large, certainly not a long open slot).

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  5. #5
    Ben Liu's Avatar
    Ben Liu Guest

    Default Re: maximum gap between stairs and wall

    The gap between the tread and wall is only 1" and is there to help provide drainage so that water doesn't pool on the treads (the stairs are in an open atrium). There is a 1.5" gap between the handrail and wall, so it would be very difficult to stick your foot in the 1" gap.

    The stairs are not part of an emergency fire escape- they are the normal means of egress and entry for the second floor.


  6. #6
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: maximum gap between stairs and wall

    Quote Originally Posted by Ben Liu View Post
    The gap between the tread and wall is only 1"

    so it would be very difficult to stick your foot in the 1" gap.

    I would not count on it being as difficult as you think, stranger things happen ALL THE TIME.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  7. #7
    Join Date
    Apr 2021
    Location
    OH
    Posts
    1

    Default Re: maximum gap between stairs and wall

    I have a similar question regarding the gap between stairs and wall. In my situation it is within a single family residence. I want a stair built along side a natural stone veneer wall with a 24 inch high clerestory window inset 3 inches from face of stone veneer. The stair string passes in front of the window. I prefer to have a handrail/guardrail only on one side of stair (open side opposite the side against the wall). What does residential codes (I live in Ohio) say about leaving a small gap (1 inch or less) between the stair stringer and adjacent stone wall? In addition, there is a 3 inch ledge created by the inset of the window from the face of stone. This "window sill" is solid, but it will also have a small gap (1 inch or less) between the face of stone and edge of stringer that passes in front of the short window. What does residential codes says regarding this window condition immediately next to a stair? I assume the glass must be tempered glass, but what other requirements would be imposed? Thanks for your help.


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •