Cast-In-Place Enclosure

[charlie b]

A new office building?s design includes a remote alarm for DG fuel tank level. It will consist of a light, a horn, and a reset button, all in a single enclosure about 12 x 18 inches. It will be close to the refueling station, so the operator knows when to pump up the day tank. Our architect doesn?t want an ?ugly box? hanging on the outside wall. He suggested having the enclosure (for the alarm components) cast into the wall, along with the conduit leading to the enclosure from below the slab.

Are most normal enclosure boxes (e.g., Hoffman) built to take the pressure of concrete being poured all over and around them? How is this sort of thing normally handled? Would you frame out a hole with boards, pour the concrete, remove the boards, and mount the enclosure within the hole? If so, who is responsible for making sure the hole is sized and located such that its cover plate (with door lock) fits snuggly against the wall?

 

[Bob NH]

I would make the hole size the responsibility of the architect and structural engineer. There will need to be special reinforcement around the hole to prevent cracking. If possible, the panel cover should be oversize to allow a nice radius at the corners, as sharp corners almost always result in cracks (architect and structural responsibility again).

The depth of the alcove should be large enough to permit shimming to get the cover to match with the surface. There might be some studs cast in the back of the alcove to allow adjustment and mounting of the box.

The architect wants the beauty of a flush panel. Let him suffer the pain and cost of designing the installation.

 

[petersonra]

Dairies do this kind of thing all the time.

The ones I have seen look a lot like a normal enclosure with a flange for mounting to the wall so it can be grouted into an existing rectangular cutout in the concrete wall.

All the ones I have seen are custom made, but I think Hoffman actually makes some for this purpose, but I have never seen them used.

 

[Cow]

I've seen a hole framed out oversize in a wall. The enclosure was then placed in the hole and anchored. Mortar was used to fill the gap around the box, came out looking pretty good.