Outdoor Wiring Question

[DerbyDad03]

I have some questions about installing an exterior outlet.

I have a circuit that has 2 exterior lights and an exterior GFCI receptacle on it. I want to tap into this circuit and add another GFCI. I plan to tap into the circuit along a run of romex inside my basement, go out through the house rim joist & deck ledger and then to the outlet. I plan to run Schedule 40 PVC straight out along one of the deck joists to the far end of the deck.

Here are my questions:

1 - Is it OK to attach the GFCI receptacle, in an weather proof box, to one of the joists that support my deck? The underside of the deck is about 6 feet off the ground and I want to hide the outlet behind the front rim joist of the deck.

2 - Assuming it OK to mount the box under the deck, would it be better to mount the box such that the receptacle faces down towards the ground or out towards the next joist?

3 - The junction box inside the house will be just inside the rim joist and I should be able to connect the PVC directly to the junction box. Should I run individual conductors from the junction box, through the PVC, to the GFCI or is there a special type of Romex for this application?

Thanks for any suggestions.

[RBM]

Yes, make sure the unused threaded knockouts are properly sealed (with sealent) and you must use a "while in use" cover

Either way is OK, but facing down, the cords may pull out

Three individual conductors is fine. Romex is fine as long as it's not considered a "wet location". A conduit in the ground is a wet location, but I don't believe one strapped to the underside of a deck would be considered one

[dpb]

I'd use wet-rated cable or conductors anyway for exterior use -- cost differential can't be but a few dollars at most for this size of a project and what can a little extra caution hurt? Wet-rated Romex is available and would be ok if the run is protected from physical damage by the routing, otherwise protect it w/ conduit.

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[Doug Miller]

Make sure you use PVC electrical conduit that is approved for exposure to sunlight. Ordinary PVC water pipe will degrade in a matter of just a couple of years, and is *not* Code-approved for electrical use.

Sure.

Doesn't much matter, as long as you have a weatherproof cover for it.

Either one is OK.

[Doug Miller]

Sounds like a damp location to me: "...Examples of such [damp] locations include partially protected locations under canopies, marquees, roofed open porches, and like locations..." [2005 NEC, Article 100]

[RBM]

If your PVC is continuous, you can pretty much use any standard building conductors inside it, however if it's not continuous, or as dpb said, if you choose not to use a conduit, you can use UF cable stapled to the joists, but be sure to use rain tight UF threaded connectors at the weather proof box

[John Grabowski]

If the run is going to be hidden, you could make it easy on yourself and just use UF cable stapled to the joist of the deck. You would need a compression type connector to enter the outdoor outlet box, but only a romex connector in the basement. The UF cable would need a smaller hole than the PVC through the house.

Yes, it is okay to do that.

Whichever suits your needs, however if it faces outward you will need a "In use bubble cover". If it faces down I think a standard weatherproof GFI cover will suffice.

It is easier to pull individual conductors into the conduit. If you want to pull Romex I would use 3/4" PVC conduit.

[mm]

You may not need another one, but I don't understand the rest of the post well enough to say. Any outlet downstream from the current GFCI will have the same protection if you connect it right. There are only two reasonable ways, and maybe it's marked which one is which.

OTOH, if you are just using the circuit but are on a tributary that the GFI is not on, not upstream from, then you have to get a second gfi.

[DerbyDad03]

re: Make sure you use PVC electrical conduit that is approved for exposure to sunlight. Ordinary PVC water pipe will degrade in a matter of just a couple of years, and is *not* Code-approved for electrical use.

Doug,

Thanks for this reply and the later one about "damp locations". I'll go with individual conductors.

BTW I don't know where you live, but in the area around Lake Ontario, the sun shines down on our decks, not up from below. (kidding!) The PVC will be run along an interior joist, so there is no danger of UV degredation. Beside, I'm going to use Sched 40 PVC.

Thanks again!

[DerbyDad03]

"if you are just using the circuit but are on a tributary "

This is the case, so I need 2nd GFCI.

Thanks for the response (everyone)

[RBM]

Sch 40 PVC only describes the thickness. Doug's point is to use electrical PVC not plumbing PVC

[Doug Miller]

I was picturing it on an exterior joist, where it would be subject to sunlight, but even under the deck and on an interior joist, there would still be some sunlight filtering through the deck boards, although probably not enough to harm it. In any event, PVC water pipe isn't approved for electrical use, whether or not it's exposed to sunlight.

You're welcome. Glad I could help.