Anyone know a source of info that illustrates the do's and don'ts for making conduit sleeve-type penetrations in fire walls? I'm particularly interested in finding out how long a sleeve has to be when it sticks out of the sheetrock. Different inspectors in different lacalities have come up with different interpretations and I don't know what to think anymore. I have seen specifications for conduit sleeves that require a minimum of 1" and maximum of 2" sticking out from the surface, and I have run into inspectors that require 18" sticking out. Is this just a local issue, or is there some national standard that is unevenly enforced, or inadequately understood?