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RE: Conduit in concrete slabs

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1.If this is for a "quality" building: Government, University, hospital, etc.:  Do NOT allow it in the slab. The owner will be drilling into the wiring as soon as they remodel. (probably during the punchlist. Try to sort that argument out!)
2. If the panelboards are grouped and are near a shaft, you will be surprised at how conduit they can get into your slab. I had one job that has four 96 position panelboards at two locations on each floor. The panels are on a concrete shaft/shear wall.  400 3/4 inch to 2 inch PVC conduits are in the slab at the same place that the dowels are spliced from the slab to the wall. 200 or so 1 inch comm. conduits came to the wall further down, with four 4 inch chases through the slab. I convinced the EOR to allow EMT spacers to keep the conduit off the splices. I am convinced there is more conduit than slab concrete within 20 feet of the panels. I would personally not allow conduit in the slab here. The spec's did. (The fire alarm sub got in late and missed putting his conduit in the slab)
Summary: do not allow if spec's back you up. The subcontractor might save a little going in, but the owner will pay in the future, and you will be sick if you see the amount of concrete left out near the conduit termination point. (Assuming normal electrical, an not just an isolated run.)
Bill Hartman, P.E.
 -----Original Message-----
From: Paul Feather [mailto:pfeather(--nospam--at)]
Sent: Wednesday, July 24, 2002 3:37 PM
To: SEAOC List
Subject: Conduit in concrete slabs

Hello All,
I am looking for consensus on the current practice regarding the permitting of conduit in elevated concrete slabs.  We are reviewing our specifications.
I am considering three categories, conventional, post-tensioned, and concrete over metal deck.  Also, do you differentiate between rigid conduit and the currently popular plastic flex conduit.
All input is appreciated.  We are accused of being out-of date and too restrictive (what else is new).  I will be happy to repost a summary once it is compiled.