My wife is pregnant with our first and I work from home so I decided to move my office out to the shed to make room for a nursery. Here is the shed.



The biggest questions I have are vapor barrier and splitting one of the incoming electrical wires 3 ways. I explained a little further but 1 will go directly to outlets and the 2 other splits to a light switch box (one to control interior lights and another for exterior). Thanks for reading my post and any tips are welcome, thanks!

Windows

• I found a great deal on some 2nd hand windows from craigslist window set 1 and window set 2
• A friend of mine is coming to help with these, he has installed windows before so I'll learn a ton from this process. I'm assuming I'll need 2x4s to frame them up and flashing/other materials
• I will also install a small window unit for a/c directly into the wall AC unit runs at 4.8 amps and will have dedicated 20A circuit

Electrical

• I had an electrician come by and install this small sub panel which can handle up to 60A.
• I plan to run 2 12/2 Romex circuits underground in a 3/4 inch PVC conduit, using 3 90 degree bends. Will probably bury 6"-1' deep.
• These 2 will be connected by 20A breakers at the sub panel.
• Circuit 1 will be dedicated for the A/C unit and heater.
• Circuit 2 will be split 3 times coming into the junction box. The first split will go directly to outlets. The 2nd and 3rd will go to light switches (one for interior ceiling and another for 2 outside lights)
• I have my brother in law coming in town who has done a couple electrical project in his rent houses, so I think we can tackle this
• Any issues here?

Internet/Coax

• Will be running coax and a cat 6 in the same size conduit as the electrical (but will be a separate conduit) That cable is rated for direct burial, but if I'm digging the trench for the electrical, I might as well put these two in a conduit too.

Insulation

• Will be using r13 standard rolls and a staple gun to install the insulation
• I live in San Antonio and the shed is lifted about a foot off the ground (plenty of airflow) so I'm not sure if a vapor barrier is necessary. I have spoken with a couple shed builders and employees at Lowes and they don't seem to think it's required here.

Walls

• Using 5/8-in x 4-ft x 8-ft sheets of drywall. Screw directly into studs
• Will tape and fill in gaps as necessary with plaster, etc. May end up adding texture as well

Flooring

• I plan on using plywood and staining/adding polyurethane coat, very similar to this example

Door seals & sweeps/threshold to keep out bugs & keep in cold.

I can't help you with electrical, but i can advise on the vapor barrier.

From your description, it seems that you do not plan on removing the exterior siding, which means installing a vapor barrier on the interior side of the wall before insulation would probably prove ineffective. The usual method is framing, sheathing (plywood or an exterior sheetrock), weather or vapor barrier (Tyvek paper is most popular in residential), then your exterior siding (brick, plaster, hardiboard, etc.).

Are you planning on dropping in a ceiling? I ask as i do not know how the exterior walls meet the roof line on that type of shed. You may want some eave/ridge vents if you plan to create an "attic space".

Hennessy11 said:

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Electrical

I plan to run 2 12/2 Romex circuits underground in a 3/4 inch PVC conduit, using 3 90 degree bends. Will probably bury 6"-1' deep.

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I believe this has to be at least 18" per code. Someone maybe able to confirm. That is what I remember from working commercial electrical as a gopher. I would go deeper than 1 foot.

I've also heard to lay caution tape on top of the conduit. Maybe also put a pull string in the ethernet/coax (and electrical?) conduit if needed down the road.

Consider running one larger circuit out to the shed and setting a panel at the shed. Not sure on the code requirements for distance to the disconnect, but it would make things easier if you want to add a circuit or move things around.

Hennessy11 said:

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My wife is pregnant with our first

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Congrats!

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Electrical

• I had an electrician come by and install this small sub panel which can handle up to 60A.
• I plan to run 2 12/2 Romex circuits underground in a 3/4 inch PVC conduit, using 3 90 degree bends. Will probably bury 6"-1' deep.
• These 2 will be connected by 20A breakers at the sub panel.
• Circuit 1 will be dedicated for the A/C unit and heater.
• Circuit 2 will be split 3 times coming into the junction box. The first split will go directly to outlets. The 2nd and 3rd will go to light switches (one for interior ceiling and another for 2 outside lights)
• I have my brother in law coming in town who has done a couple electrical project in his rent houses, so I think we can tackle this
• Any issues here?

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Romex, i.e. NM cable, isn't meant to be run thru conduit. It can be done in certain applications, but not really this one. Underground conduit is defined as a wet location which is a no-go for NM cable. Aside from that, the sheath is rather tacky and stretchy. Pulling two cables thru a single 3/4" conduit with three hard bends for what looks like a decent enough distance is going to be a mofo. I'd suggest using plain wire rather than NM, something like XHHW which is made for a wet location.

The thing is, however, your shed is a separate building. You can feed it with a single feeder or a multi-wire circuit. Your two circuits is neither. Will it work? Yes. Is it kosher? No. To be kosher, you'd need a single feeder from the existing subpanel to a different subpanel at the shed, along with some sort of disconnecting means at the shed (main circuit breaker in the shed subpanel or a separate disconnecting means). You'd also need a ground rod at the shed bonded to the grounding conductor of the feeder.

Corps_Ag12 said:

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Door seals & sweeps/threshold to keep out bugs & keep in cold.

I can't help you with electrical, but i can advise on the vapor barrier.

From your description, it seems that you do not plan on removing the exterior siding, which means installing a vapor barrier on the interior side of the wall before insulation would probably prove ineffective. The usual method is framing, sheathing (plywood or an exterior sheetrock), weather or vapor barrier (Tyvek paper is most popular in residential), then your exterior siding (brick, plaster, hardiboard, etc.).

Are you planning on dropping in a ceiling? I ask as i do not know how the exterior walls meet the roof line on that type of shed. You may want some eave/ridge vents if you plan to create an "attic space".

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Good call on the sealing, Going to go the extra mile and make sure everything is sealed well.

Correct, I don't plan on removing the exterior siding so I don't know how much a vapor barrier would actually doing being between the sheetrock and framing.

I do plan on doing a ceiling and have considered installing a ridge vent or two in the roof. I'll take some pictures tomorrow of the easing to give you an idea if there is any room for it to breathe.

Satellite of Love said:

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Hennessy11 said:

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Electrical

I plan to run 2 12/2 Romex circuits underground in a 3/4 inch PVC conduit, using 3 90 degree bends. Will probably bury 6"-1' deep.

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I believe this has to be at least 18" per code. Someone maybe able to confirm. That is what I remember from working commercial electrical as a gopher. I would go deeper than 1 foot.

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Will do. I've read this as well so I think I'll try and get as deep as I can. Being in the hill country, it's going to be extremely rocky and will probably need to rent a trencher if I can't get it by hand.

pnut02 said:

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I've also heard to lay caution tape on top of the conduit. Maybe also put a pull string in the ethernet/coax (and electrical?) conduit if needed down the road.

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That's not a bad idea at all. Something like this?

UnderoosAg said:

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Hennessy11 said:

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My wife is pregnant with our first

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Congrats!

Quote:

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Electrical

• I had an electrician come by and install this small sub panel which can handle up to 60A.
• I plan to run 2 12/2 Romex circuits underground in a 3/4 inch PVC conduit, using 3 90 degree bends. Will probably bury 6"-1' deep.
• These 2 will be connected by 20A breakers at the sub panel.
• Circuit 1 will be dedicated for the A/C unit and heater.
• Circuit 2 will be split 3 times coming into the junction box. The first split will go directly to outlets. The 2nd and 3rd will go to light switches (one for interior ceiling and another for 2 outside lights)
• I have my brother in law coming in town who has done a couple electrical project in his rent houses, so I think we can tackle this
• Any issues here?

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Romex, i.e. NM cable, isn't meant to be run thru conduit. It can be done in certain applications, but not really this one. Underground conduit is defined as a wet location which is a no-go for NM cable. Aside from that, the sheath is rather tacky and stretchy. Pulling two cables thru a single 3/4" conduit with three hard bends for what looks like a decent enough distance is going to be a mofo. I'd suggest using plain wire rather than NM, something like XHHW which is made for a wet location.

The thing is, however, your shed is a separate building. You can feed it with a single feeder or a multi-wire circuit. Your two circuits is neither. Will it work? Yes. Is it kosher? No. To be kosher, you'd need a single feeder from the existing subpanel to a different subpanel at the shed, along with some sort of disconnecting means at the shed (main circuit breaker in the shed subpanel or a separate disconnecting means). You'd also need a ground rod at the shed bonded to the grounding conductor of the feeder.

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I read up on that this afternoon and you are right. If I go with THHN or XHHW, does that mean I have to run 6 wires? (2 circuits of 1 hot, 1 neutral, and 1) or could I go with something like this?

I'm not too familiar with what a single feeder means here, mind explaining? Adding a subpanel to the shed, is this to accomplish a quick access to a disconnect? If so, the distance from the shed door and breaker (sub panel) is only about 50 ft. It's actually closer to the breaker than my current home office is inside the home.

Depending on how long you plan on using this, I'd give serious thought to giving it a decent foundation with a brick or cinderblock perimeter, 10 mil plastic vapor barrier on the earth and a couple or 4 vents with screens on them. Otherwise, these things do tend to rot out from the bottom up.

Why can't he run this in the conduit?

https://m.lowes.com/pd/Southwire-250-ft-12-2-UF-Wire-By-the-Roll/3129375

I would step it up to 2 inch so it isn't so difficult to pull.

Or are you saying NEC says only one circuit is allowed to a separate structure unless you sub panel ?

I'm in San Antonio if you need some help. I'm planning on building a shed next spring, so I wouldn't mind getting a little experience.

Let me preface this by pointing out again there is a difference between what will work, and trying be fully code compliant. You asked for the time and I think I'm giving you the history of the watch.

THHN and Romex aren't rated for wet locations. THWN, XHHW, and UF cable are.

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Why can't he run this in the conduit?

https://m.lowes.com/pd/Southwire-250-ft-12-2-UF-Wire-By-the-Roll/3129375

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UF, like NM (Romex) are cable assemblies. This is going to sound stupid, but running a cable thru a conduit depends if it is really a conduit or not. If you had a j-box on the house with a continuous conduit run, with fittings, LB's, whatever, to another box at the shed, then you have a conduit system. If you put a cable into a conduit system, you have to be concerned with fill ratio and potential de-rating.

If you had sections of conduit that were not complete, for example the conduit just stubbed up below the shed and the cable came out exposed and ran into the shed, then you do no have a conduit system. In this case, it's a sleeve, or more appropriately "protection from physical damage". However, if you had conduit just stubbed up like that, you're begging to get water and miscellaneous crap in it. So you could use UF in conduit, but I'd look hard at the cost first. It will depend on quantities, and buying per foot versus in a roll, but there will come a point where plain wire is cheaper than cable.

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Or are you saying NEC says only one circuit is allowed to a separate structure unless you sub panel ?

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Quote:

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I'm not too familiar with what a single feeder means here, mind explaining? Adding a subpanel to the shed, is this to accomplish a quick access to a disconnect? If so, the distance from the shed door and breaker (sub panel) is only about 50 ft. It's actually closer to the breaker than my current home office is inside the home

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Distance doesn't matter. With a few exceptions unrelated to this, any building needs to have a disconnecting means at the building and can only be fed by a single circuit or feeder. The "disconnecting means" can be up to six handles, meaning a subpanel with one main breaker, one disconnect switch, a collection of up to six disconnect switches, or a subpanel with no more than six circuit breakers in it. It's often referred to as the six handle rule because the idea is that you shouldn't have to flip more than six handles in order to completely de-energize a structure, albeit at that structure.

A circuit, or a branch circuit, is the wires coming from a circuit breaker in a panel someplace feeding lights, receptacles, a fridge, an AC unit, etc. A feeder is the wires coming off a circuit breaker feeding another panel. You have a main panel someplace. There is a feeder from that panel to the subpanel in the photo. Your plan is to run two branch circuits from the subpanel to the shed. But that's a no-no.

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n. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s)


225.30 Number of Supplies. A building or other structure that is served by a branch circuit or feeder on the load side of a service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.

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The A thru E exceptions don't apply here. Your options become either using a subpanel at the shed such that you have a single feeder, or you cut it back to just one circuit (which won't really work with the AC unit).

BUT WAIT, THERE'S MORE!!

The last line says a multi-wire circuit is considered a single circuit. A multi-wire circuit is essentially two branch circuits which share the neutral and ground. You may consider your two circuits run out to the shed a multi-wire circuit if they share the neutral and ground, AND, they are both shut off simultaneously**, meaning they are fed from a two-pole circuit breaker. In this case, you'd have, say, a black hot from one pole, a red hot from the other pole, a white neutral, and a green ground run to the shed. When you get to the shed, use a 2-pole toggle switch as your disconnecting means, then run the black to the AC unit and the red to the receptacles/lights. The multi-wire circuit also takes care of no longer needing the ground rod.

If it were me, I'd add a subpanel to the shed, but only because I like to play with my toys. This isn't my shed, so going back to your original question of what wire

1. UF cable, 12/3 with ground. This gives you the hot, hot, neutral, and ground. I'd only use this with no conduit.
2. #12 THWN or XHHW, black, red, white and green in a 1" conduit. Gives you some more room to pull, and a little extra space if something comes up down the road. 2" is even more room, but then your fitting prices jump quite a bit. Use premade 90 degree elbows for bends, and use LB fittings where you turn into the shed. Shouldn't be too bad, but you can also get Yellow 77 or something like this to help grease the skids

http://www.homedepot.com/p/Klein-Tools-32-oz-Premium-Synthetic-Clear-Lubricant-51028/100660159

** There is a catch to using multi-wire circuits. You have to be very careful in how you wire devices, and how/where you split the circuit. Black to neutral or ground will measure 120V. Red to neutral or ground will measure 120V. Black to red will be 240V. If you get something caddywhompus, there is the potential for sending 240V to, say, a receptacle that has your brand new laptop plugged into it. The same thing can happen if you were to somehow lose the neutral at any point along the way. . When you wire the receptacles and light switch, pigtail them, don't go directly thru the device.

I would run 3 #6's and a #10 THHN in a conduit, put a 6 circuit panel on the exterior then you will have more capabilities to put your 2 20 amp circuits plus extra. That disconnect may be rated for 60 amps but I would verify that they ran at least a 6-3 romex to it and have a 60 at the main panel.

I've done basically the same project you're doing, thought it was a garage rather than a shed. Trust me....spend the money and rent a trencher. It will be the best money you spend.

Another point on the electrical line:

When you bury it, put on top of it the RED electrical tape (think police yellow tape, but red). Put the conduit, then the tape, then dirt.

That way if someone starts digging and they hit the plastic tape, they know there is something underneath.


As far as the internet/cable, I would put it in a conduit and put a couple of pulling strings. That way, if something comes around later (fiber, the next best thing, etc.) you can pull the new line without digging a new line.


Also, I would go with like 25% capacity of any lines buried. Leave room for additional items. So if you only need a 1/2" line, go up to an 1" or 1 1/2" line. Also makes pulling future lines easier.

~egon

Yessir!

Add at least one spare 1" with pull string