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Re: 1930's Poured in Place Concrete Building

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Dennis,
 
A change in occupancy may result in a requirement that the Building comply with the modern Building Code -- see 1997 UBC Section 3405.
 
Figure out the reason for the deterioration.  Most likely, is poor drainage -- moisture that is not drained sway from the building can saturate the base of the wall and rise by capillarity until it makes its way to the wall surface and evaporates.  In this case, the culprits causing deterioration are salts dissolved from the soil or concrete that crystallize when the moisture evaporates.  The crystals form within the surface of sound concrete and break it up leaving efflorescence on the wall, and fine dust of deteriorated concrete on the ground -- which will probably be blown away between storms, but will probably remain at the base of the wall inside.  Include stormwater control in the project.  Also, look for evidence of corroded rebar -- this causes cracking that follows the rebar pattern, and also causes spalling of larger pieces of debris that will not get blown away.  Expose corroded rebar and re-embed it in fresh mortar before you cover it all up and hide the problems with gunite.
 
[Dennis, thanks for the personal note -- I'm looking forward to hearing from you when you get the chance.]
 
Nels Roselund
Structural Engineer
South San Gabriel, CA
njineer(--nospam--at)att.net