Switchback Stair clearance / opening

[ACADuser]

Looking at the minimum width opening required for interior residential stairs I came up with 6'-6 1/4" drywall to drywall.

That is given a 2" handrail, 1-1/4" balusters and a 1" side tread overhang.

 

Does that look correct to you folks?

 

Thanks

 

 

[Kbird1]

It may depend on Local Codes but I thought the staircase had to be 39" ( 3'3" ) not 3' ?

 

I think CA's Staircase is 39" by default too ?

[ShaneK]

It would pass code in Michigan because or minimum is 36" CLEAR opening, no obstructions allowed.

[Joe_Carrick]

According to the CRC which I believe is exactly the same as the IRC:

 

  Minimum width above handrails is 36".

 

  Handrails are allowed to project as much as 4.5" into the 36" minimum width

 

  Minimum width at and below handrails is 31.5" when the handrail is only on one side.

  Minimum width at and below handrails is 27" when the handrail is on both sides.

 

  Based on the above, assuming no tread overhang on the open sides you can have a switchback stairway of 6'-0" drywall to drywall.

 

Note that a "Guard" on the open sides could actually be at the same location as the handrail.

 

 

[ACADuser]

Joe Florida Building code has the same language.

So this would be the tightest design. 

36" clear to the adjacent tread side overhangs.

[ACADuser]

I think I have it boiled down to this.

 

[Joe_Carrick]

That's pretty good but in my neck of the woods we have to actually dimension what is going to be.  Just referencing a code section is frowned on because the builder and/or tradesmen may not actually have access to the code.