Mezzanine inside PEMB

[masterthenight]

My firm is designing the foundation for and the mezzanine framing inside of a PEMB. The mezzanine occupies about half the area inside the PEMB and extends to the building perimeter on three sides. We are located in SDC A. I am thinking I should design the mezzanine to stand independently inside the PEMB.

My question is: Assuming the mezzanine is properly braced for lateral forces, is there any reason structurally to attach the mezzanine to the PEMB framing? It seems these two elements should be independent to allow the PEMB to deflect under lateral loading. Should I just ensure there is a proper gap between the PEMB and the mezzanine framing?

 

[msquared48]

Keep it separate laterally, and, yes, allow for a space between the PEMB walls, X bracing, and mainframes.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[JennyNakamura]

Keep it separate as Mike says. The PEMB was probably not designed for the additional lateral mezzanine loading anyway, and PEMBs are usually designed for the bare minimum design loads.

 

[pittguy12]

If your project falls under the requirements of IBC, there is criteria in there about building seperation (basically sum of the squares of ampified story drift). Section 1613.6.7 for IBC 2009.

 

[vthomidis]

...yes keep it separate and allow for a gap between PEMB and mezzanine framing....
( "the mezzanine occupies half the area" :..it's rather a pity
though that the mezzanine coloumns will "interfere" to the
spacy clear span of the PEMB ....)

 

[JedClampett]

I'd definitely design it separate, like everyone is saying. There's an excellent chance when the project is bid, that the PEMB supplier will ask to design it as part of the building, but that way you're covered, plus you have a minumum level of design already on paper.

 

[masterthenight]

Thanks so much for all your replies. I understand the PEMB is typically not designed for additional loads apart from the code minimums, unless specified by the EOR.

I do have one tricky situation. There is a 2nd floor exit out of the building from the mezzanine. I am guessing I will need to design a slip joint here. Any thoughts on a detail to accomplish this? The mezzanine will be wood framed.

 

[msquared48]

Yes, I agree that you will need one there.

Just use two overlapping metal plates, one attached to the PEMB framing, and one attached to the mezzanine framing.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com