Concentrated load capacity of an existing slab on metal deck from 1975

[jochav52802]

Good Day,

I'm working on a project where our client wants to hang a new 1/4 ton monorail/hoist from an existing 6" thick slab on 3" metal deck designed in 1975.

The existing drawings don't specify the metal deck profile or thickness, they just call for 3" metal deck.

I'd appreciate help with the following questions:

1) Any recommendations for how to obtain the SDI catalogue/specs for 1975 era metal deck? If I can't locate this information, any suggestions for how to confirm that the slab on metal deck can handle the new loads?

2) Since there is so much existing HVAC, there isn't room to add new framing to support the hoist beam. So, the current plan is to drop end-plated HSS posts that are anchored to the underside of the existing floor deck with Hilti expansion anchors to support the hoist beam; since the load is so small, the anchor check easily passes the code check. Are there any concerns with anchoring to the underside of a slab on metal deck?

Thank you!

 

[jayrod12]

Is the existing slab reinforced such that the metal deck was only used for formwork? That'd be my bet from that era. Composite decking wasn't as popular then as it is now.

 

[jochav52802]

Unfortunately, the general notes just say it's 3" deck and direct us to see the specs, which we don't have, for it's design. I was going to assume it's non-composite and hope I could get it to work.

 

[BAretired]

Do you know how the slab was reinforced? If so, does it work without the metal deck? If not, how would you know if you can get it to work?

BA

 

[jochav52802]

Hello BA,

Yes, the slab is reinforced with #5's @ 16". I'll check to see if it works without the metal deck.

Thank you

 

[JedClampett]

SlideruleEra has my old Robertson catalogues from the seventies.