I have a question concerning placing pvc conduit through the walls of a concrete underground vault, which will be poured after forming. I will have 30 2" pvc conduits (3 rows of 10 runs, horizonally) entering one side of this vault, and 6 6" entering another side of the vault. The specs show the layout, but does not show the procedure for installing them into the sidewall forms.

I have used voids or sleeves inside the plywood sides of the concrete forms before, but never for this many conduits. Is using voids, or sleeves, or drilling the plywood form and installing the conduit, the best way? If drilling, how close to actual conduit size do I have to be, to keep excess concrete from flowing out of form? Or is there some trick to seal these before pouring?

The specs also call for the 6" PVC to have bell ends flush with the floor when it enters the building next to this vault. Will duck tape work to seal the ends while the floor is poured, or is there another way? What is the purpose of limiting it to the floor level? I believe these runs will be entering into the bottom of high voltage switchgear, so I will probably extend stub-ups a few inches after the floor cures. Sound ok?

Any hints on doing any of this would be appreciated.

Rick Miell