Conduit through concrete slab of composite steel beams

There are some general guidelines in ACI 318, 6.3 that should be referenced.

Additionally, I do not allow any reinforcing to be displaced from its designed position. All conduit must be contained between the top and bottom layer of reinforcing. Do not allow conduit to be bundled but it must be spread apart 3 diameters minimum. If two or more conduit crosses in the slab, the sum of the diameters of the conduits cannot exceed 1/3 the depth of the slab and must not displace any reinforcing. The conduit must not cross composite girders or beams within the middle half of the span (in other words, locate the conduit near the ends of the beams). The structural engineer will have final approval over the placement of all conduit in the slab before it is poured. You might even insist on having a meeting with the electrical contractor before the placement of any conduit.

I suggest placing all this info. on the electrical drawings in a highlighted note so there will be no surprises for you or the contractor.

I hope this helps!

I think there is another thread discussing this here:


At my office we just adhere to ACI 318 section 6.3