Slab on Metal Deck Openings without Reinforcing 1

[Boiler106]

Im redoing our slab on metal deck opening typical details and looking at maximum opening sizes without reinforcing (in the US).

Most drawings from other firms call for either 6" or 10" max diameter openings without reinforcing.

Is there a reference or methodology for selecting these sizes? Perhaps, its rule of thumb? Does SDI have something?

For reference, most of these decks are 2" composite with 3 1/4" LWC topping or 4 1/2" NWC topping.

 

[MrHershey]

The old Verco manual had some good typical details for openings in composite deck. Page 30/31 here: Link (PDF)

They note the reinforcing is mainly for the construction condition. They also note that individual holes <6" typically don't need to be reinforced.