UF into watertight box on deck?

Discussion in 'Electrical Forum discussion & Blog' started by ironspider, Aug 26, 2011.

  1. ironspider

    ironspider Member

    Jul 26, 2008
    Greetigns all, I've had great advice on my last two questions so I'm back with stage 3!

    Okay, so we're having our deck expanded and when the old deck was torn up it revealed some UF cable running safely along the bottom of a deck joist (stapled to the lower edge of a 2x10) that ran into a sunroom. After having this wire tracked down it turns out it used to control some outdoor lighting that has since been removed (it was replaced with a different lighting layout that is powered and control from elsewhere in the house).

    So, this UF (12/2) is simply diconnected in a box in the basement. It travels outside via an LB in the basement, a short run of conduit, and then exposed along the joist. This part is all underneath a covered section of the deck.

    So, i can simply connect up this wire to the active power feed coming into the box and have power on that cable. I'd like to use that cable to now run the other direction on the deck to the edge of the deck and install a waterproof/watertight receptacle.

    My question is, I know that UF can be run along the bottom edge of a deck since it is not in "danger of damage", and I'd like to avoid running conduit as I don't think it's required [for the long run along the bottom of the joist], but how do I go into the receptacle box? Do I have to use some conduit before I enter the box? Or do they make watertight fittings that can attach directly to the box so that I can run the UF cable straight into the box?

    What I'd really like to do is come straight out from behind the edge joist into the back of a watertight box. So the watertight receptacle box is mounted on the perimeter of the deck but no conduit is.

    Here's a quick drawing of what I'd like to do (on top) and what I'd like to avoid (on bottom):

  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Jun 14, 2007
    North Carolina
    yes come into the back of the box. When you drill the hole through the joist make sure to make it large enough to handle the connector you install into the ko in the back of the box. Also be sure to use the deep box to have room for the GFCI device.
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  4. Jim Port

    Jim Port Electrical Contractor

    Aug 22, 2009
    Electrical Contractor
    The fitting for the UF will have a compression gland that will tighten down on the cable.
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