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Re: code load for stairs?

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On March 9, Jeff Smith wrote the following:

-------SNIP-------

> Can anyone tell me if they feel that the 100psf code live load is intended
> for interior private stairs of a residential unit with an occupant load less
> than 10? (Not public stairs or fire escapes, but possibly a required means
> of egress for within that unit.)
>
> Does not seem like a bad idea, but I was just curious what the intent of the
> code is.
>
> Jeff Smith, S.E.
>

-------SNIP-------

My interpretaion of the 1994 UBC is that 100 psf live load is required on *all* stairs that are part of an exit facility.

1994 UBC Table 16-A, item 5, refers to footnote 5.  Footnote 5 says:

"Exit facilities shall include such uses as corridors serving an occupant load of 10 or more persons, exterior exit balconies, stairways, fire escapes and similar uses."

I interpret this to mean that reference to an occupant load of 10 or more applies *only* to corridors.  In other words, in a single family dwelling, corridors would be designed for 40 psf live load, but the other items would be 100 psf, including all stairs that are part of a path of travel to an exit.  If the intent of ICBO is that occupancies of *less* than 10 persons should have the *stairways* designed for 40 psf, then the wording of footnote 5 should read something like this:

"Exit facilities shall include such uses as corridors and stairways serving an occupant load of 10 or more persons, exterior exit balconies, fire escapes and similar uses."

What's the general consensus?  I'd also be interested to know if anyone knows of an interpretation/clarification of this that has been published in Building Standards magazine.

Mark T. Swingle, S.E.
Oakland, CA