acceptable conduit in spray foam applications

[crewchief437]

looking for what i can use to run electrical in walls that will be closed cell spray foamed after installation. im not drywalling at this point, so have to use conduit.

 

[rockwithjason]

Anything you can use in a regular wall will be legal to use here. I would look at aluminum flex or emt. You may want to experiment with the flex and see if the foam would intrude on it.

 

[crewchief437]

just thought about this, additionally the wire is to be covered or placed in conduit to be in code. is embedded in foam considered covered? basically am i required to put in conduit under the foam or should i

 

[rockwithjason]

If it cannot be grabbed or snagged or otherwise touched then it is covered

 

[Eriehunter]

You could use romex or mc cable provided they are legal in your area. Flex is a good option but I would pull the wire before foaming or at least install a pull string. I like EMT as it gives alot of options for the future but is more costly to install.

 

[warren57]

Several choices
Rigid (galvanized threaded pipe) most difficult and expensive.
EMT with compression fittings. Pretty easy and affordable.
BX cable. Higher to buy, easiest to install. Likely a good option.
Why conduit anyway? Romex is fine. Tape openings on boxes. Once dry, foam is just insulation... Romex is fine in unfinished walls. Look in any unfinished basement, garage, or crawl space. They are full of romex.

 

[crewchief437]

yeah im basically looking for the cheapest route that doesn't cost me a ton of time. im putting in a ton of outlets plus 3 240 drops and a dedicated compressor line so im not overly worried about additional wiring. if romex is cheaper than conduit i would likely go that route. if normal wire in emt is cheaper i would go that route. hope this makes sense. i want to do it the right way just trying to save where i can since the money is mounting quickly.

 

[69gp]

yeah im basically looking for the cheapest route that doesn't cost me a ton of time. im putting in a ton of outlets plus 3 240 drops and a dedicated compressor line so im not overly worried about additional wiring. if romex is cheaper than conduit i would likely go that route. if normal wire in emt is cheaper i would go that route. hope this makes sense. i want to do it the right way just trying to save where i can since the money is mounting quickly.

If it were me I would go with the EMT. Couple of reasons if you want to add a lot of outlets. You can install the EMT now and just pull 1 or 2 circuits at first if you do't have the money. 2nd EMT will make it very flexible if you should change equipment around at a later date pull additional 220 volt circuits. If you pipe it in now and can mount all your boxes and ****** them together. Just install blank plates if you do not use the box right away.

What if you forget a circuit? even if the attic is accessible you will never be able to fish the wall.

 

[alfredeneuman]

If you're going to use NM cable, you'd better be sure that the spray foam doesn't interact with the insulation on the cable.

Personally I think that the EMT idea is the wisest, for the reasons given in previous posts.

What about PVC Rigid Conduit. It has enough "give" to be run between the studs, where the EMT doesn't.

 

[volleyball]

You might want to rethink the drywall as you cannot leave the foam exposed in an occupied room. Use romex, foam and drywall. You can just slap up joint compound to fire seal it and paint or not.

 

[Orionrising]

Check with the foam maker but most sprayfoam needs a fire barrier. Its is reflective an insulative enough it flashes once temp floor is reached

Sent from my LG-L38C using Tapatalk 2

 

[Bib Overalls]

From the stand point of wiring a closed in building, PVC conduit is a better option than EMT. As noted above PVC has some flexibility and you will need that when you work the conduit through the studs. I have seen EMT run through stud walls before the sheathing was applied. Takes a lot of forethought and attention to detail to pull something like that off.

Conduit will give you future flexibility that you won't have with Romex. But Romex will be cheaper to buy and faster to instal.

 

[Cmreschke]

Emt is cheaper than flex. Pvc is cheaper than emt. Romex is cheapest by far, but less forgiving if you miss something after the fact. I would not go with Pvc if your going to pipe it in. You will need bigger holes and steel is easier to pull through.

 

[alfredeneuman]

I would not go with Pvc if your going to pipe it in. You will need bigger holes

3/4" EMT has an outside diameter of 0.922"
3/4" PVC has an outside diameter of 1.050"

That's a little more than a tenth of an inch.

 

[mjwelte]

We did a house with foam in the walls and just ran Romex and low voltage in the walls and sprayed over. As with all projects once everything was sheet rocked up the homeowner decided to add a couple of electrical outlets and wanted to add CAT5 in the low voltage runs. There was no way we could change anything. With the changing technology and electrical requirements I would run it in EMT. We do that now for all projects as it saves us a ton of money in the long run. It is a pain in the beginning but that foam is a PITA to deal with after the fact.

Mark