partition weight vs. cubicle weigh

huangyhg

partition weight vs. cubicle weight
situation:
an existing building - structural framing is wood - doing calculations to determine live load capacity.
code says:  office live load = 50 psf plus partition live load of 20 psf where partition locations are subject to change.
client may want to (or we would recommend) opening up the space for general office use - but with cubicles...no partitions.
are cubicle's weight considered part of the 50 psf live load (furniture) or are they part of the partition weight?
so if we get a live load capcity of 55 psf, the 50+20 = 70 doesn't work unless we say "no partitions on this floor", and the client comes in with cubicles, are we ok?
opinions?
i always thought cubicles were partitions.--though i never really thought about it.
i would consider cubicles partition loading.  some can be awfully heavy and much more closely spaced than full blown partition walls.  it seems that the 50psf live load would be the books, computers, cabinets, and everything else people cram into the cubicle space.
if the actual partition dead load is less than 20 psf, use that.
mbones
initially i would assume that cubicles are same as partitions as stated by others above. however, as an engineer, one must use due diligence and try to determine the type of cubicle they intend on using and contact some manufactures for psf loading.
i think you will find that 20 psf is adequate. the 20 psf covers a 2x4 stud partition with plaster on both sides. with steel type partitions, the real load may be around 4 to 5 psf.
good luck
lutfi - you hit on a point that is unique here - the 20 psf is based on some plaster-type walls which really don't get built all that much anymore in my neck of the woods.  
cubicle weights can be verified and i'll do that - but the code is silent on whether that weight is ll or partition - they are really just big furniture - with cubicles, you don't have desks, file cabinets, etc. - those are all built into the cubicle so it seems to me that you're counting load twice by including it as partition.
anyone else?
jae - a few "outside the box" thoughts:
1. the modern definition of partion seems to be a total and complete separation, like a partion on a computer's hard drive. to me a partion in a building would go floor to ceiling and have doors.
2. cubicles seem to be "furniture", they are purchased at the office supply (furniture) store. partions are "constructed".
3. in the past, perhaps the increased load requirement for "partitions" was to help limit floor deflection to keep that plaster from cracking. floor deflection is probably not a significant problem for cubicles.
i beleive that 50 psf meets the intent of your code requirement. just some thoughts.
i like to add to the discussion the effects of modern day "paperless office" which reduces the true live load on a floor coupled with lack of real partitions that give us the nasty floor vibrations that people complain about. i would like to hear percentage numbers of the real acting live load on floors these days. i would guess some where below 20%!
now going to the opposite end of the spectrum where we design office floors for 50 psf and the owner/user begins to use the floor as a storage space at some time in the future.  i know as engineers we have no control over that unless we are consulted by an alert owner/user at the time of conversion.
just thinking loud here