Wiring Question

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  #1  
Old 04-19-05, 11:55 PM
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Question Wiring Question

Hi - First I just wanted to say hello and that this forum is loaded with great information(I've been lurking for a bit).

I'm pretty much a beginner, but I need a project to keep me busy and I'd rather learn how to do all this stuff by myself rather than paying somebody.

Here goes:
I'm planning on finishing a room in the basement of my townhouse(it's about 13x14, and it was roughed in when it was built). The building is only 5 months old.

Since I'm going to want to add a new circuit for some outlets, I started to take a look at the existing wiring. A lot of the wiring that is pre-existing(Romex), is stapled to the upper edge of the studs/joists and running the length of the room instead of through holes drilled through the studs and joists. I'm wondering if this is normal? If everything is fine with that, I'm wondering what I can do to protect the wiring when I hang the drywall?

I also noticed a couple runs of wire that come down the front of the stud and then go into the stud bay, rather than having a hole drilled through the studs. I think this might be because it's an exterior wall and drilling through the 4-5 stacked 2x4's would have been too much. How would I protect this while drywalling?

The circuit I'm planning on adding is a 20A GFCI breaker with 4 20A receptacles, and run with 12/2 NM wire. I might also add some recessed lights to this circuit, but I'm not 100% sure of that yet.

Thanks for the help!

 
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  #2  
Old 04-20-05, 01:37 AM
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First off you should get down to your HomeDepot, local bookstore, or public library and get a couple of good books on DIY home wiring. Try Wiring Simplified or Black & Decker's Basic Wiring or HD's Wiring 1,2, 3.

NM cable must be physically protected. This usually means stapled to the sides of the joists/ studs if the cable runs parallel and holes drilled through the studs/joists if the cable runs perpendicular. The cable needs to be 1 1/4" from the surface of the drywall or it must be protected with a 1/16" plate. If the cable runs along the surface of the wall, it needs to be protected. This is often accomplished by running EMT or PVC sleeving.

NM cable running perpendicular to the basement ceiling joists can be protected by a board or boards running alongside that cable for the full length. Same thing for an attic.

A couple of websites to augment your book reading:

http://www.selfhelpandmore.com/homew...ling/index.htm
http://www.hylandbros.com/HowTo/wiring/ewiring.htm

Post back if you have more questions and good luck.
 
  #3  
Old 04-20-05, 02:20 AM
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Thanks for the response. I already have the B&D book and I'm planning on making a trip to the library to take a look at the 2002 NEC book(already have the MA state amendments).

I guess I'm just a little confused as to why the builder wired the room the way he did.

Let me see if I can do a better job of explaining how the room is set up - I'm trying to figure out how I can protect the existing wires giving the way the builder has layed them out.

Part of the wall is already drywalled with 5/8 inch drywall. At the very end of this drywalled section, a NM cable comes down through the ceiling and is stapled along the stud(it's an exterior wall) as it runs the length of remaining unfinished wall. In order for me to drywall the unfinished section and make it flush, I would pretty much have to drywall over the unprotected NM wires. I know I can't do that - so I've been trying to figure out a way around it. If I were to run an additional stud alongside the wire to protect it, the wall would not be flush with the existing wall.

I suppose I could just cut the drywall and only finish the wall up until it reaches the wiring and then just use a larger drop down ceiling - that way I wouldn't need to protect it. Would that be a good way to avoid this problem or are there other ways to resolve this issue?

Thanks again for the help, I appreciate it.
 

Last edited by 99gixxer; 04-20-05 at 02:21 AM. Reason: grammar
  #4  
Old 04-20-05, 02:43 AM
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I wouldn't bother trying to read the NEC until you have considerably more experience. Otherwise, it could lead you astray. The problem with beginners reading the NEC is (1) the words may not mean what you think they mean, and (2) you cannot apply one article in isolation, so you really need to read the whole thing.

There are a lot of "ifs, ands and buts" when it comes to protecting NM cable, and the differences are in the details. For example, what is allowed for one size wire may be prohibited for another size wire.

The solution is lots of reading. Read at least three books--six would be better. If you don't want to buy them, most libraries have a decent collection.
 
  #5  
Old 04-20-05, 03:17 AM
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Originally Posted by 99gixxer
Here goes:
I'm planning on finishing a room in the basement of my townhouse(it's about 13x14, and it was roughed in when it was built). The building is only 5 months old.

Since I'm going to want to add a new circuit for some outlets, I started to take a look at the existing wiring. A lot of the wiring that is pre-existing(Romex), is stapled to the upper edge of the studs/joists and running the length of the room instead of through holes drilled through the studs and joists. I'm wondering if this is normal? If everything is fine with that, I'm wondering what I can do to protect the wiring when I hang the drywall?

I also noticed a couple runs of wire that come down the front of the stud and then go into the stud bay, rather than having a hole drilled through the studs. I think this might be because it's an exterior wall and drilling through the 4-5 stacked 2x4's would have been too much. How would I protect this while drywalling?

Unless you want to put a lot of notches in the wood and nailing metal plates (see link) to protect the cable, I suggest doing it right, like it should have been done in the first place.

http://www.electrical-supply.net/pro...A_prodID_E_192
 

Last edited by thinman; 04-20-05 at 10:04 AM.
  #6  
Old 04-20-05, 08:00 AM
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It sounds like the person who did the wiring assumed the room would never be finished. Still, it is a code violation to run NM cable on the bottom of joists unless a runner board is installed. And at the very least, it was extremely short-sighted for the installer to run NM on the face of the studs. The only solution I would consider, personally, is ripping it all out and installing new. As suggested/recommended by otheres in this thread, staple the NM cable on the sides of studs and joists, 1-1/4" min. from the surface the drywall will go on, and drill through the studs and joists in the center (top to bottom for joists, front to back with studs) to run NM cable perpendicular. You will also likely have some issues with boxes. Boxes installed in an area intended to remain unfinished are often not installed in a way or a location that is logical for a room with finished walls. They may be flush with the surface of the studs or joists, which will not work if you add drywall. The box should protrude 1/2" from the face of a stud or joist to be flush with the drywall when it is installed. There is usually a little ridge on non-metallic boxes that is 1/2" from the edge, which is a feeler gauge for drywall.

Hope that helps.
 
  #7  
Old 04-20-05, 03:18 PM
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Thanks again for all the replies and suggestions. Boxes aren't a problem since they didn't install any...that was the reason why I was going to add another circuit and outlets.

Here is what I'm thinking of doing...please let me know if this sounds ok. Since most of the cables that run along the studs are against the wall holding the breaker box, I'm just going to build a new wall off of the existing concrete wall. In front of the breaker box, I'm going to install some bifolding doors to make access to the wiring and breaker box easy.

I'm also planning on building a new wall in one additional small section to keep the drywall away from unprotected wiring as well as to leave room to access the outside faucet shut off.

As for the other wall - it has a single run of NM wire stapled along the stud. Since I don't want to rewire the entire run, and it only runs under 4 joist, I'd just like to drill a "conduit" at the bottom of the joist, a couple inches away from the wall, and move the wire from the stud face into the conduit. Since the conduit would just be at the bottom of the joist, I'd add a metal strike place to protect the wire.

Does anyone see any major problems with this?

Thanks again.
 
  #8  
Old 04-21-05, 02:57 AM
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Originally Posted by 99gixxer
I'd just like to drill a "conduit" at the bottom of the joist, a couple inches away from the wall, and move the wire from the stud face into the conduit. Since the conduit would just be at the bottom of the joist, I'd add a metal strike place to protect the wire.

Does anyone see any major problems with this?
I am not sure what you have in mind, but I would caution about drilling or notching the joists near the end of the joists where the vertical shear stress is highest. I think there are some restrictions about that sort of thing.
 
  #9  
Old 04-21-05, 03:02 AM
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Maybe it's just me, but it seems like more work to build a new wall, put NM in conduit, and notch the studs than it does to just drill holes in the center of each stud and run new NM cable through the studs in the conventional way. It's fast, easy, cheap, safe, and to Code.

Just my $0.02.

Juice
 
  #10  
Old 04-21-05, 05:01 AM
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Originally Posted by JuiceHead
Maybe it's just me, but it seems like more work to build a new wall, put NM in conduit, and notch the studs than it does to just drill holes in the center of each stud and run new NM cable through the studs in the conventional way. It's fast, easy, cheap, safe, and to Code.

Just my $0.02.

Juice
The new wall is going up regardless...so it was just an easy solution for that side.

The reason that I didn't want to run a new NM cable is that the wire comes from upstairs, runs along the stud, and then goes back upstairs, so rewiring the entire thing is something I really don't want to do.

However, given the concerns you noted, I'm thinking about just cutting the wire, adding 2 junction boxes and running a new wire between the junction boxes through the joists like it should have been done originally.
 
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