I'm in Pa and iI can't seem to find anything explaining this. I am building an addition and trying to save as much space as possible. My question is, if i have a half wall at the top of the floor and a 31in cleareance between the half wall and room wall down to first step leading to the basement, would that be okay? Would that first step down be required to be a landing?

Thanks.enter image description here

  • I think International Residential Code requires a minimum depth of 36" for landings, but I'd have to check the code to be sure.
    – Tester101
    Feb 28 '17 at 14:47
  • The depth is over 36" from the back wall to the stair entrance but the width is not. There is no door going here either. Feb 28 '17 at 16:21
  • Depth is measured in the direction of travel on the stairs. So "depth" is the distance from the beginning of the landing, to the wall you'd be looking at if you were standing on the stairs. See this image for clarification.
    – Tester101
    Feb 28 '17 at 16:30
  • The stair stringer in your picture needs to go a long way to the right for this to be safe, Not surprisingly it also needs to do that to meet code. As it stands you have a 2 or 3 step drop from the opening to the right-most stair-step in line with the opening. That will cause falls. If you really want to save space on stairs, spiral is about as good as it gets, but they can be impractical to move things up and down.
    – Ecnerwal
    Feb 28 '17 at 17:28
  • Oh, that string is sitting under the platform so it wouldn't fall. Tester101, I'll have to check back on that image. It won't load right now. Thank you. Feb 28 '17 at 19:11

Yes, a landing is required at the top and bottom of residential stairs. The simple answer is it should be 36" in the direction of travel. (There is an "exception" to that, but does not apply to you. )

To solve your problem, (and I get points taken off my "reputation" for offering advice that doesn't stick to the question, but I'll offer it anyway...) try a 2 or 3 step winding step stair (pie-shaped treads) for the last few steps. Basically you're making a 90 degree "left-turn" at the top of the stairs. There are several requirements to those steps, which I'm not smart enough to figure out, but basically each step should not be less than 6" wide "where you walk". Where-you-walk is defined as a point 12" from the narrowest point of each step... Oh, the widest depth of a "winder " step can't be more than 12" at furthest point out...

Don't forget the handrail (mount between 32" and 38" from nosing of each step.) Handrails in residential construction is required on one side of stair only.

  • Oh, and that wall "guarding" that opening to the stair needs to be a minimum 36" high from the FINISH FLOOR with no openings that would allow a 4" sphere to pass through.
    – Lee Sam
    Mar 1 '17 at 3:21
  • Thank you very much. From what I am reading, "R311.1.10.1 Spiral stairways. Spiral stairways are permitted, provided the minimum clear width at and below the handrail shall be 26 inches (660 mm) with each tread having a 71/2-inch(190 mm) minimum tread depth at 12 inches (914 mm) from the narrower edge." Does that mean that I could have a spiral for the 90 degree degree turn at the 26" then jump back to 36" normal stairs? Mar 1 '17 at 4:54
  • I don't know, but I doubt it. Winding stairs are not spiral stairs. Confusing, I know. (See IRC, chapter 5, section R311.7.4.2. ) See if you can figure it out... They do talk about code differences between rectangular treads and "winder" treads, but not spiral treads. Spiral Treads are a section of their own.
    – Lee Sam
    Mar 1 '17 at 5:36
  • Oops...Chapter 3, not 5.
    – Lee Sam
    Mar 1 '17 at 6:12

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