I’d like to add an outlet box to the underside of my deck. Easiest way seems to run 12/2 UF sunlight resistant cable (~40′) directly from breaker inside the house, through the open framing in basement, and along the underside of the deck to an exterior box with a GFCI outlet. By my read of the NEC, since all wire will be within framing, no need for conduit, and UF is usable in same applications at NM interior. Sound proper?
I know- get an electrician- but I’d like to know the “correct” way before I proceed. I need to get an electrician for the permit regardless. I guess I’ve seen too many shorted wires and shoddy work to just sub it out blind.
Replies
be safe...
tube the wire in the exterior application...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
I wouldn't bother with conduit.
You get out of life what you put into it......minus taxes.
Marv
Definitly go with conduit. The wires will be exposed to damage within the open deck joists. I'm not sure if it's code required (seems like it should be!), but it's cheap and good peace of mind.
keeps the squirrels out too...they like romex.
Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
The wires will be exposed to damage within the open deck joists.
Damage from what?
Ed
The wires will be exposed to damage within the open deck joists.
<< Damage from what? >>
Who knows? wildlife, freeze/thaw cycles, an errant broom handle? Why chance it?Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
Romex in conduit??? Careful about clarity here.
Why not use BX cable?
MArtin
BX is not for exterior uses... I agree with the idea of uf in conduit.
Basically sounds good. The cable should enter from the side or (better) bottom of the box, to minimize moisture entry chances.
Sunlight-resistant UF should be fine (and almost overkill) if reasonably protected within the deck structure. Plastic conduit or watertight flex would add a small amount of additional protection (UF is pretty rugged by itself), but hard to say if it's worth the trouble without seeing how complex the install would be.
Note that if you use the plain UF you may need additional mechanical protection near the box, depending on how it's exposed. Also, some consideration is needed re the entry of the cable into the house, both in terms of mechanical protection and water exclusion.
Some clarification- the deck is about 2-3 feet off the ground, so no traffic underneath but I suppose potentially some animals could get in there. The wire would come through the ledger board and be tacked to the side of a joist all the way to end of deck- or at least that is what I envisioned.
I thought about conduit, but I've heard conflicting things about the propriety of running UF in it for extended lengths (in this case, the exterior portion of the run is 16'). It would not be that difficult to run. Can the conduit terminate indoors in the framing with a nipple and then continue with the UF to the breaker? I didn't want a box at the interior/exterior line since the framing will be covered eventually.
Thanks!
UF is more rodent-resistant than regular romex. We were using it in Puerto Rico because of it's added rodent resistance. It may well be more rodent-resistant than standard plastic conduit.If you carry conduit into the house, you should be able to terminate it with just a bushing (to prevent the conduit end from cutting the cable), vs having a box where the cable exits.The rules about derating multiwire cable in conduit are a little obscure, so some code lawyer will have to quote you chapter and verse. Keep in mind, though, that UF is larger/stiffer than regular romex (if indeed you use UF in the conduit) and will probably require larger conduit.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
There is no code for derating cable in conduit. Cable is conduit is treated just like individual wires in conduit for the purpose of deraing.No more heat buildup being in conduit than being burried in the middle of an insulated wall.For pulling cable in conduit you need to treat it as a single wire the diameter of the larges dimension of the cable.Conduit can also be used to sleave wire to protect it from physical damage (needs to be sch 80 if PVC). While the code does not specficially say anything about practice is to all a smaller condit where the cable just fits. For examp to protect a NM drop from the joist to the receptacle on a basement wall..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Seems like every time the issue of cable in conduit is raised there's a different answer on derating.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
There are only two answers.One that the code is silent on this.And all of the wrong ones..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.