Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

How to make an electical outlet box on 2x2 wall up to code?

How to make an electical outlet box on 2x2 wall up to code?

Reply

  #1  
Old 12-26-09, 04:38 PM
W
Member
Thread Starter
Join Date: Dec 2009
Location: USA
Posts: 39
Received 0 Votes on 0 Posts
How to make an electical outlet box on 2x2 wall up to code?

To start, my local code states that they conform to state code, which in turn states that the tate code conforms to the national code, so that should make answering my question easier.
I am finishing my basement, and on two walls I put on 2x2's for frame work (1-1/2" thick I believe). On the two walls I have put up a total of 3 receptacles (2 outlets each). These were placed in shallow metal boxes which I believe are 1-7/8" deep. I am using #12-3 cable for these. The reason being I have outlets elsewhere that are controlled by a switch and I am using the third wire to feed the switched power to those other outlets.
I recently was reviewing code regulations and found that for two 12-3 cables and two outlets in a box, the required space comes out to:
2 white wires x 2.25
2 black wires x 2.25
1 ground x 2.25
1 or 2 red x 2.25 (the red does not connect to the outlet, instead it connects the the other red vie wire connector, I am not sure if this counts as one or two wires)
2 outlets x 2.25
This comes to 18-20.25 cubic inches.
Then also do I need a cable connnector? If so, ive noticed there are some that take up more space inside than others, do some not count towards the 2.25 cubic inches that a cable connector needs.
This total amount of space needed exceeds what the standard box i have now, which is 2x4x1-7/8" (15 cubic inches). I was wondering if anyone had suggestions.
One solution I have thought about is getting a 4x4x1.5 box and getting metal cover that converts it to a single gang raised by 0.5 in. My only question then for this scenario is it up to code once the drywall is placed over part of the box with only the 2x4 opening, the rest behind the drywall is coverd in metal and it sounds like that is fine for the code. If this is not good please let me know if anyone has a good solution, or if it will work, is there anything else I should be mindful for? Also, if the box is 1.5 in deep and so is the 2x2, will the thickness of the covers cause a hump in the drywall?
 

Last edited by wvphysics; 12-26-09 at 05:14 PM.
Sponsored Links
  #2  
Old 12-26-09, 04:52 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 5 Votes on 5 Posts
This may give you some good reference as to what you are trying.Box Fill Calculations (NEC 2002) - Self Help and More
 
  #3  
Old 12-26-09, 05:17 PM
E
Member
Join Date: Dec 2009
Location: Kentucky
Posts: 24
Received 0 Votes on 0 Posts
The 4x4 box with a single gang plaster ring covered with drywall is code compliant. The only other way is to check out behind the box so you can place a deeper box.
 
  #4  
Old 12-26-09, 05:40 PM
W
Member
Thread Starter
Join Date: Dec 2009
Location: USA
Posts: 39
Received 0 Votes on 0 Posts
Thanks, I had already used similar info from the website to make my initial calculation, however it did answer my question about clamps, if I read correctly it said only count clamps that extend further than 1/4" into the box.
With the 4x4 idea being compliant, my only question now is if the cover would cause a hump in te drywall or if Mayr a 1-1/2" deep box is actually slightly less than 1-1/2" to make room for cover and screws.
 
  #5  
Old 12-28-09, 12:52 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 43 Votes on 41 Posts
Originally Posted by wvphysics View Post
my only question now is if the cover would cause a hump in te drywall or if Mayr a 1-1/2" deep box is actually slightly less than 1-1/2" to make room for cover and screws.
It will probably make a small hump, but not too bad -- maybe 1/8". If you have poured concrete walls you can chip 1/4" or 1/2" off the surface to get a little more depth to set the box. You also might need to notch the back side of the drywall a little bit to recess the mudring mounting screws so they don't hold the drywall out.

Also be careful to run your cables along the back of the furing; code requirement for cable placement is 1-1/4" back from the nailing face of the framing members.
 
  #6  
Old 01-06-10, 07:56 AM
E
Member
Join Date: Dec 2009
Location: Kentucky
Posts: 24
Received 0 Votes on 0 Posts
Best way is using the 4x4 with a plaster ring to match your drywall thickness. It won't cause a bulge in the drywall. To satisfy the 1 1/4" rule for NM cable (romex) use something called a colorado jim. These will hold the romex off the 2x4 (and out into the space between the 2x4s) and not allow screws/nails to puncture the romex.
 
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: