Replies

1. 
   Sphere | Dec 20, 2003 12:25am | #1

   buy the recptacles first. Then back engineer it. run conduit, stub it up, pour ,cutout the green concrete, put in box to check fit. Remove box. Yes they have covers for unused , screw in plugs. after all the rough work is done ( including carpet, or what have you) pull wires, put in box. A little pl glue and yer all set.

2. 
   blackcloud | Dec 20, 2003 12:34am | #2

   Linkster,

   You can not have your cat 5 and power in the same box in most area's.  It is also bad for the reason that the power will interfere with your Phone/network connections.

   Jason

   If it wasn't for bad luck I wouldn't have Any!
1. 
   4Lorn2 | Dec 20, 2003 11:55am | #3

   Do yourself a favor. Avoid the PVC floor boxes. The best floor boxes are galvanized steel, though I haven't had the pleasure I hear there may be some newer adjustable PVC boxes that are good also, with an adjustable sleeve that is screwed flush once the concrete is set.

   You set them a bit low before the pour, with the sleeve fully retracted and protected by a thin tin lid, and remove the eighth of an inch of cream over the top once the concrete has set. Then you move a sleeve up with a set of screws to bring the box lip perfectly flush with the finished floor

   Also avoid the plastic covers. Spend the cash and get a high quality brass version from manufacturer of the box. Once the box is adjusted the cover will screw in nicely and give a highly stable base that can be readjusted if the floor covering is changed.

   The cheap PVC boxes depend on a slip fit and are adjustable up only by using shims. Too often I have seen these end up spongy or so loose the cover are often kicked loose.

2. 
   DaveRicheson | Dec 21, 2003 08:27am | #4

   CAT 5E can be share space in a box with 120v ac recepticals. It can not share the same conduite run. There is a simple shield that seperates the two side of the box. I have installed thirty or so multipyl use boxes in the raise panel floor of our Data Center, with multipyl 120v , cat5e and coax connections in them.

   Setting a floor box to finish grade is pretty straight forward, if you know what the floor finish is going to be, and have a bench mark established. Run the conduite to the box location and stub it up well above finish grade. Cover the conduite with gravel, lay down the plastic and wire mesh as you would for a normal concrete pour. After that prep work is done, go back and cut off the conduite, add the box at finish floor grade and tie wire it to a couple of light gauge metal stakes to keep it level. Depending on the concrete crew,I may make the support stakes just tall enough to support the box and let them stay in the pour, or, if I trust the crew, make the stakes extra tall and have them pulled out as the floor is poured. The last is my preferance, because it means I know the box will end up level with the slab finish.

   The box, adjusting ring, divider shield, and box cover I have used in poured floors are made by Hubbel.

   Dave

3. 
   Frankie | Dec 21, 2003 06:06pm | #5

   Run separate conduits for reg. voltage and low-voltage.

   Rather than bending the conduit, we use elbow connectors. This helps getting the proper vertical length when installing the box LATER. Run vertical pipe 6" AFF and be sure they are oriented in opposite sides of the gang box.

   Next, create a void for the box, by cutting and stacking enough square peices of rigid foam insulation, or using a wide enough cylinder to accomodate the gang box installation after the pour.

   A few notes:

   a) As a further precaution, cover the elbows with lots of gravel so they can be accessed later.

   b) if you use foam, the 2 vertical pipes will seem to hold the foam in place but it would be a good idea to ram 2 lengths of rebar through the foam and into the ground to be sure. Pouring concrete is not a TLC type of job.

   c) You know what they say about the best laid plans... Especially when installing a tile floor, you may find you want to orient your floor box with the grid of the tile or centered on a particular tile. For this reason you may want to either create a MUCH larger hole or resign yourself to the fact that you will be doing some cutting into the slab during box installation. Having a connector on the horizontal length of conduit already there will help.

   I hope this helps.

   F.