Vented Deck for Parking Deck?

[BDH12]

What is the current thinking on concrete slabs on vented metal deck for parking garages? (Assume that I am using slab on deck one way or another. Not cast-in-place, post-tensioned, etc.) I am aware that vented deck was recommended years ago, but it was my understanding these decks have been found to not perform well because it encourages the moisture to move through the bottom of the slab, causing corrosion and dripping on cars below. I have thought that non-vented deck with a breathable sealer or membrane was the preferred system these days. Also, SDI's position seems to be that vented deck is to allow moisture to escape the slab as the concrete cures, not to let rain and melting snow move through the slab after the sealer fails. Two very different things. I have been given a recommendation to use a membrane on vented deck, citing a reference that is almost 15 years old. I'm not sure if this is good advice or perhaps outdated. Thanks!

 

[jayrod12]

Are you just intending on using the deck as sacrificial formwork? That would be the only way I would touch that idea, vented or not.

That's a big no-no in our area where road salts are used constantly.

 

[JAE]

Are you referring to AISC's Design Guide 18 - Steel-Framed Open-Deck Parking Structures? (2003)

You might call AISC's office to see if there is any new documentation or information on this.

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[DETstru]

Vented deck is not recommended by SDI.

Link:

http://www.sdi.org/wp-content/uploads/2013/11/PPVENTR2.pdf

 

[BDH12]

Thanks for the feedback everyone. Yes, the deck is completely sacrificial and not part of the structural design. The consultant I am dealing with is referencing DG 18, but as you have pointed out, SDI has since issued a position statement that seems contrary to DG 18. I am not comfortable with a membrane on top of the slab if the moisture mitigation through the bottom is negligible. I think you have confirmed my original position. Thanks again.