Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: code load for stairs?

[Subject Prev][Subject Next][Thread Prev][Thread Next]
    Mark, I believe you are correct.  When I was SEAOC Code Committee representative to ICBO, a code change similar to the wording you proposed was submitted, I believe, by the ICBO Peninsula Chapter but was disapproved.  All stairs must be designed for 100 psf.  See also San Francisco Building Code 2317.9.1 which limits wood (exterior) stringer spans to 7 feet and requires 3x12s if the span exceeds 5 feet unless an engineering design is provided.

Bob Bossi

Experience is simply being able to recognize
a mistake the second time you make it.

"Mark T. Swingle" wrote:
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."