loads 2 ceiling of processing plan

huangyhg

loads @ ceiling of processing plant
i am in the design phase of a poultry processing plant.  the temperature on the processing floor is kept at 40 degrees f.  the ceiling above the floor is made up of insulated panels.  the panels do not support anything.  however, they are used by maintenance personnel to get to mechanical equipment and piping.  the roof is long span steel joists supported at the perimeter and at interior beam lines.  my question is what bottom chord live load to specify for the joists (and to design the beams around)?  the code used is ibc 2000.  the number of maintenance personnel could be up to 10 at one time.

there isn't a direct ibc live load for this other than, i think, a 10 psf for "ceiling" load.  there is also a 25 psf live load given for catwalks.  i would think that i'd start with using the 25 psf live load and test it against the 20 guys you describe.  visit with the owner and see how these personnel work together, etc. to get a feel for their tendency to congregate in a small area.  
very practical answer jae.  in the past i have just gone with the minimum recommendation for live loads that the codes give (as abiguous as they are, sometimes), but i think that observing and studying the traditional load patterns (whether the loading was intentional or not) of our structures is exactly what we engineers should be aware of.  once again, very pratical!
in canda, we have a load case that gives a udl of 10 psf live over the bottom chord that we have to incorporate as a minimum. this is for workers, etc. may not be code in the states, but not a bad starting point.
geoff