Mechanical room live load

[WWTEng]

IBC 09. I have an existing building where they want to place a new air-handling unit on an existing elevated slab (concrete pan joists). The original use of the area was a classroom. The equipment load works out to about 60 psf (rounded up by 10) and the slab works for this load. However I have always seen new-building mech rooms designed for 125 psf min or equipment load, whichever is greater. IBC does not specify a min load for a mech room. So my question is, am I ok using the equipment load of 60 psf?

 

[msquared48]

If you can show that it works and it is posted as such for future equipment changes, you might be able to convince the jurisdiction, however you may not be able to term iit a "Mechanical Room". Also check out ASCE7, section 4.7.2 (02 ASCE 7 here) Machinery, as you may need to increase the load for impact.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[Portcullis]

Determine if mechanical engineer is planning on setting the equipment on a new concrete housekeeping pad (installed on top of the existing slab, typically 4" to 6" thick, to elevate for drainage, etc.) which would greatly increase new total loading.

 

[WWTEng]

Portcullis: Yes, they were planning a 4" conc pad, I told them that wasn't going to work is its going to be a steel curb, 6" high, much lighter.

 

[WWTEng]

M^2: Thanks. I agree with the placard suggestion.

 

[asixth]

I use a different code where the minimum loading for mechanical rooms is 100psf (5kPa). We generally design our mechanical rooms for 150psf but the mechanical equipment never comes in this high, it is normally around the 60psf mark.