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-   -   adding 2nd floor circuit by running wires outside in PVC - advice? (http://www.diychatroom.com/f18/adding-2nd-floor-circuit-running-wires-outside-pvc-advice-77428/)

reags 07-29-2010 12:01 PM

adding 2nd floor circuit by running wires outside in PVC - advice?
 
Hi,
I need to run an additional 20A circuit to the second floor from a finished (drywalled) basement - no good inside routes I can find without multiple drywall patches (and likely a lot of frustration). Here is what I would like to do:
NM-B (12-2) from service panel in basement to J box inside basement but near outside wall - connect to THWN in junction box - run THWN (12awg, three wires) to exterior and up the outside of house to enter attic. Junction box inside attic to transition from THWN back to NM-B 12-2. All THWN - from junction box in basement to Jbox in attic - would be inside 3/4" PVC 80.
Now for my many questions -
First and foremost: plan OK, or is this flawed/over complicated, or should I cut up drywall in many places and try to go inside?
What intervals to secure the PVC to the house - every 4ft?
Do I need an expansion fitting in the PVC (20-30ft vertical run outside (Northeast US)
Can I run up to 6 12awg wires in 3/4 PVC 80 for up to two 20AMP circuits? I figure I might run addl wire while the work is being done in case a separate 15 or 20AMP circuit is ever needed upstairs.
What have I not considered?
Thanks!

Scuba_Dave 07-29-2010 12:05 PM

I would never run PVC up the outside of a house
Looks terrible, just my opinion
More junctions - more possible problems

Proby 07-29-2010 12:11 PM

PVC on the outside of the house is very common for services, there is nothing wrong with it.

That said, running pipe of any kind on the outside of the house for branch circuits is the easy way out and I usually try to avoid it, especially if it could be seen from the street or the backyard area.

Opening up some drywall and patching it is very easy, especially if you plan a good route which will limit the amount of holes. Many times you can find a chase going from your basement to your attic, either where the plumbing runs up or around the chimney framing.

You attic is the second floor or the third floor?

nap 07-29-2010 12:17 PM

you can run it up the outside if you want. Ugly in my opinion but legal.


be sure you seal the pipe where it goes from inside to outside. It is to prevent warm moist air from migrating into a cooler area and the moisture condensing. It is a code requirement.

schedule 80 would only be required where it might be subject to damage. Otherwise, 40 is fine.

wire fill 1/2" = 6 #12's, 3/4- 12 #12's. Don't forget to count the egc for wire fill count.


you need a support every 3 feet

expansion characteristics 100 temp range= 6.08mm/m
I used the 100 as it probably fits your area close enough.
so, that means you will have about a 2" variance in length over 30 feet. Yes, a slip fitting would be a good idea.

also, be sure to NOT fasten the conduit so tight it cannot slip within it's attachments.

reags 07-29-2010 12:34 PM

Thanks for the advice/thoughts. Proby - attic would be the the "3rd" floor.
Agree it is not optimal, but was looking for opinions/other options, and feedback on the method and materials if I chose that route. Neither electrician that came out really even considered fishing inside - they saw the drywalled basement ceiling and ruled it out. Maybe they just took the easy way out (one even wanted to run UF under the vinyl siding with no protection) since it's not their house. Anyway, I guess if I just resigned myself to the fact I may have to cut and patch a lot of drywall I could find a way, although an "easy" route inside does not exist. The PVC would be on the side of the house where the service comes into the house and next to a downspout, so the ugliness of the whole thing would be minimized, but frankly I'd always end up staring at it, so any other idea/options are always welcome. Thanks again

Proby 07-29-2010 12:54 PM

Quote:

Originally Posted by reags (Post 477237)
The PVC would be on the side of the house where the service comes into the house and next to a downspout, so the ugliness of the whole thing would be minimized, but frankly I'd always end up staring at it, so any other idea/options are always welcome. Thanks again

There really aren't any other options, either fishing it thru the walls or running up the side of the house. Remember, when fishing thru the walls you also have the option to run thru closets. If you have closets stacked on top of each other this might make things easier. But you do have to protect those wires in the closet, which is an easy task with some surface mount WireMold type products. As for running the wire thru the basement, you have the option of running the wire in the top corner where the wall meets the ceiling, then covering it with crown molding.

As for what you said about having the service and downspout and probably cable and phone lines on the side of your house, the pipe might disappear in the other utilities. Ultimately it is up to you.

Scuba_Dave 07-29-2010 01:39 PM

Prior owners ran 2 circuits thru the closets to 2nd floor at my house
Wire was exposed
I ended up drilling from the basement & 2nd floor during renovation & putting the wires in the wall

Proby 07-29-2010 02:08 PM

Quote:

Originally Posted by Scuba_Dave (Post 477266)
Prior owners ran 2 circuits thru the closets to 2nd floor at my house
Wire was exposed
I ended up drilling from the basement & 2nd floor during renovation & putting the wires in the wall

Good thing to do, always the best option. But it's a bit more complicated for a beginner, especially when they have to get thru 2 floors.

reags 07-29-2010 03:03 PM

Yup, I've fished wires into existing 2nd floor outlets boxes from the attic to wire add'l lights/switches, but never through 2 floors. Plus having little access from the basement (drywalled ceiling) is no help. I may have to resign myself to cutting a few holes and patching or going outside. If I do the former, can I run two 12-2 NM-B cables through the same 3/4" hole through the wall, or do I need two separate holes a certain distance apart?
Thanks again

Proby 07-29-2010 03:05 PM

Same hole. if you are talking about going thru the joists and other wood members, I would go with a 7/8" or 1" size hole for (2) 12-2's, much easier to pull.

You can get an auger bit at Home Depot for about $12, you'll always find uses for it.

nap 07-29-2010 03:08 PM

Quote:

Originally Posted by Proby (Post 477278)
Good thing to do, always the best option. But it's a bit more complicated for a beginner, especially when they have to get thru 2 floors.

you just start at the bottom and get a reeeeaellllllyyyy long drill.

might need an extension to hit the attic though.

Proby 07-29-2010 03:09 PM

Quote:

Originally Posted by nap (Post 477309)
you just start at the bottom and get a reeeeaellllllyyyy long drill.

might need an extension to hit the attic though.

LOL, you might need GPS guidance for the tip of the bit too :laughing::thumbsup:

nap 07-29-2010 03:11 PM

Quote:

Originally Posted by Proby (Post 477311)
LOL, you might need GPS guidance for the tip of the bit too :laughing::thumbsup:


Note to self;

next million dollar idea; GPS location for drills

reags 08-06-2010 09:48 AM

Thanks for the advice and discussion. I finally found an inside route and ran the wires this past week. Only required a small-ish drywall cut in the ceiling of the garage, so easily fixed. Took longer, of course, but am much happier with it. Circuit is in and functioning. Thanks again!

secutanudu 08-06-2010 10:22 AM

How do you seal the pipe where it goes outside? You are talking about sealing the inside of the pipe, right? I have a 1" pipe leaving my basement underground (about 12" below grade) to my lamppost. I did not seal the inside...caulk? foam?


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