EMT conduit inside walls

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

tk3000

Senior Member
Joined
Oct 27, 2010
Messages
389
Reaction score
41
Whenever possible I am using emt conduits and thnn wires instead off nm-b/romex cabling; that is mostly true when I have to remove the drywalls anyways thus creating an ideal situation for rough-in the new installation.

But, the use of emt conduit is not without its quirks (for me at least): sometimes it is not a perfect bend and somewhat crooked (especially when reusing conduit wrongly bent, etc), so asthetically it is not always pleasing... but, still, it is 1000s times better than no conduit (future proofing installation, resilient, etc). But otherwise I was wondering if that would represent any issue as far as inspection goes, like the following:

25337787299_936525afa6_b.jpg

(there is only one clamp connecting the conduit at less than 12" below the elect. box, but I believe that the box alone gives plenty of support to the conduit. ).


In the situation below I did not offseted the conduit due to the fact that it was a straight shot from the elect box knockout to the hole in the upper wall plate, hope that it is not irregular in any way. It was difficult though to clamp the conduit to the stud (frame member) given that there is a hvac ductwork besides the conduit, and I believe that code requires at least one clamp 12" from the box. Anyhow even if the emt is not clamped to the stud it is a very sturdy installation and way safer then simply using romex stapled to the stud), any ideas on how to approach clamping it to the stud in this situation.
30973411185_c33ca97784_h.jpg



As far as elect inspection goes, ideally I would like to showcase all the rough-in electrical installation+layout of conduits, etc, but then I am afraid that the elect inspector may want bitch about the other things I am doing (drywall) and take advantage of the situation that I am required to have an inspection for the electrical work to coerce me into pay for other inspections (and while I beleive that the elect inspection makes sense since there is a somewhat interrelation of dependence between you and the grid: backfeeding to the grid could actually kill a grid worker... most other inspections are a non-sense designed to extort money which are even more ludicrous when on consider that 99% of people don't pays for inspection of drywalls, etc; perhaps some other inspection are desigined to help homeowners whom don't perform any work themselves to know the job was done properly)
 
Does your area even require conduit?
It has to be a 100% faster to just run romex.
 
Overcoming the "correct" clamping is the least of your problems.

How and where the conductors terminate above the walls is an entirely different issue you'll need to address before any inspection.
 
Does your area even require conduit?
It has to be a 100% faster to just run romex.

No, it doesn't. But I wanted to make easy to upgrade or repair in the future, so I choose to go with conduit in some places, but I will still use romex in some areas where it would entail too much destruction to use conduits.
 
Overcoming the "correct" clamping is the least of your problems.

How and where the conductors terminate above the walls is an entirely different issue you'll need to address before any inspection.

Yeah, that is a good point; and it would be my next point. They are terminate above by means of junction boxes (larger junction boxes are used as hubs [ many conversion points]). There is a mixture of emt and mc conduits to connect the boxes above. The junc. boxes are not hidden below the joists but above which then also creates the issue of affixing the boxes above to some frame member: and the easy approach probably would be to use some wood blocks attached to the joists as nailers (more work though...).
 
Add wood blocking then attach the clamps- simples.

Phil

Yeah, that was the idea, but the hvac duct makes it more difficult than it sounds. Looking closer at the pic you may see a piece of 3/4 plywood I was trying to use with that purpose. I was wondering if the simple lack of a clamping there would be an issue since it is firmly connected to the elect boxes.

Maybe an angle drill attachment would do it (have to find mine though...)
 
Last edited:
While the "J" boxes also need to be accessible, there is additionally, the # of conductors which are allowed to be contained in the different size boxes, the stapling of the MC.

You have your work cutout for you.
 
While the "J" boxes also need to be accessible, there is additionally, the # of conductors which are allowed to be contained in the different size boxes, the stapling of the MC.

You have your work cutout for you.

Yeah, I realize that the the same way the conduit body has a feeling rate, so does the elect. boxes themselves (and that the wire nuts, etc, have to be accounted for as far as the filling rate is concerned). Overall, I try to use beefed up boxes to be on the same side.

25372125329_bf16c010b9_k.jpg
 
Please go here for box fill calculations. It is easier to fill in the blanks than to describe to us each and every box and the number of romexs/conductors you have in each jbox.

Again as already mentioned but very important; don't conceal any jboxes. All jboxes must be easily accessible by the NEC. Meaning, do not hide any boxes behind walls that are sheet rocked.

Still trying to understand why you decided to go with conduit. Better you than me when it comes to the labor/materials part of this project of yours. Keep in mind (which some don't know who do not work with conduit) that no run from jbox to jbox or device box etc may contain bends totaling more than 360 degrees. Oups, :hide: did you know that?
 
Please go here for box fill calculations. It is easier to fill in the blanks than to describe to us each and every box and the number of romexs/conductors you have in each jbox.

Sure, I check this out. I have book with tables showing filling rates for different box size; I am sure you have seen them.

Again as already mentioned but very important; don't conceal any jboxes. All jboxes must be easily accessible by the NEC. Meaning, do not hide any boxes behind walls that are sheet rocked.

The only elect. boxes concealed are the ones used for power outlets and receptacles which have to be behind the drywall. No junction boxes will be concealed -- that is why in the attic I brought the j boxes up above the joists


Still trying to understand why you decided to go with conduit. Better you than me when it comes to the labor/materials part of this project of yours. Keep in mind (which some don't know who do not work with conduit) that no run from jbox to jbox or device box etc may contain bends totaling more than 360 degrees. Oups, :hide: did you know that?

It is good to know that, I probably read somewhere but don't quite remember; but I tend to have the conduits short and straight (maximum of 2 90d bendings). I certainly don't know all the nitty-gritty details and that is why I check with at least two sources before doing anything.
 

Latest posts

Back
Top