Running Wiring to Attic. Weird Situation.

Reply

  #1  
Old 04-21-17, 05:33 PM
H
Member
Thread Starter
Join Date: Apr 2017
Posts: 10
Received 0 Votes on 0 Posts
Running Wiring to Attic. Weird Situation.

I'm replacing old wiring on my second floor. I think the easiest way to do this is to run 5 circuits up from my basement to my unfinished attic and then down to each room.

There is a laundry chute straight up from my basement to my attic (about 25'). In fact, there is already 1 circuit within the laundry chute (inside a 3/4" aluminum conduit). I would like to run 4 more 12-2 circuits inside that conduit (or through a second conduit).

In researching this project, I've heard that I may NOT run Romex cable through conduit, but must run separate THHN instead.

So here's the question:
Is the no-romex-inside-conduit rule for moisture reasons (which wouldn't seem to apply to my situation) or is it just a hard rule that romex should not be inside conduit for any reason no matter what?
I'd like to run romex in the conduit, but want to be safe and code-abiding.

Sorry for the long post. Any thoughts?
 

Last edited by HuskerDad; 04-21-17 at 06:43 PM.
Sponsored Links
  #2  
Old 04-21-17, 07:19 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,017
Received 42 Votes on 37 Posts
NM can be run in conduit, but the conduit must be sized appropriately. Individual conductors are much easier to run in conduit .
 
  #3  
Old 04-21-17, 07:24 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 55,171
Received 590 Votes on 555 Posts
Welcome to the forums.

The problem is not just that NM is a pain in the a$$ to pull into conduit..... by code you need to allow thermal room. You would end up with basically two NM cables to a 3/4" conduit.

It's really easy to set a junction box top side and bottom side and run individual wires between the boxes. You'd only need one ground wire. Depending on the type of circuits you are running you can share two circuits with one neutral.

If you were setting up completely individual circuits.... like arc fault type.... you'd have 4 whites, 4 colors and 1 ground wire to run.

You can fit 24 #14 wires or 18 #12 wires in a 3/4" pipe. With your few wires you'd be below the derating requirements.
 
  #4  
Old 04-22-17, 09:18 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,355
Received 47 Votes on 38 Posts
In researching this project, I've heard that I may NOT run Romex cable through conduit, but must run separate THHN instead.
The NEC does not prohibit installing NM cables in conduit, but some jurisdictions do. It would be a good idea to check with your local building office before doing it. I would also recommend using individual THHN conductors in conduit.
 
  #5  
Old 04-23-17, 11:32 AM
H
Member
Thread Starter
Join Date: Apr 2017
Posts: 10
Received 0 Votes on 0 Posts
You all have convinced me that using the THHN is the way to go. This is exactly the information I was after. Thank you all for the excellent replies.

One last question. In looking at THHN, I've seen solid and stranded. Any preference? Is one better, safer, or more useful than the other?
 

Last edited by HuskerDad; 04-23-17 at 12:17 PM.
  #6  
Old 04-23-17, 01:01 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,017
Received 42 Votes on 37 Posts
Solid is easier to terminate around the device screws. Depending on the length of conduit you can sometimes push solid between boxes without a fish tape.

Either are acceptable and equally safe.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: