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Re: [SEAOC] Stucco

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>
>To All:
>
>I'm looking for information on how stucco should be inspected and under what
>criteria (percent unbonded area, size of unbonded area, size of shrinkage
>cracks, etc.) should a recommendation be made as to whether the stucco should
>be replaced.
>
>I'm not looking for individual opinions.  I've got a collection of them
>already; and, of course, nobody agrees.  I'm looking for something like a
>quoteable code/standard or a peer reviewed paper.  I have read ASTM C926 and
>did find the USACE web site's stucco spec, but they don't give info on
>inspecting stucco.
>
>Ray Pixley 
>...

Ray,
        In a recent structural observation, I found something that might be
useful (but not the absolute answer - there never is one, is there?). You
might want to have a testing lab check out the actual mix to determine
whether the plaster was "up to code".
        We had a contractor that was going aroung telling homeowners that
the reason for their plaster cracks was because of the local "freeze-thaw"
cycle. By saying that, he was able to get to get the homeowners insurance to
pay for a new plaster job! A testing lab found the REAL reason for the
problem was because the original installer had "skimped" on the cement in
the plaster mix; i.e., the plaster tested did not have the minimum cement
required in the mix by the UBC. The innumerable cracks observed on the
structure appeeared to have nothing to do with structural problems,
freeze-thaw, etc. but probably was due to the fact that the code minimum
cement was not provided in the mix!
        As to a definitive answer on whether or not the plaster should be
replaced based on crack thickness, I can't really say. Your best engineering
judgement, I guess. I would have it tested, though, to see if the mix on
site meets minimum requirements.
                - Terry

P.S. The minimum mixes are in the UBC but, with the recent code change from
the 1991 to the 1994 UBC, I'm not sure where. E-mail me directly if you
would like more info and I'll see what I can do.

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