I'm getting ready to install electric boxes in my ICF walls.    I did a little research on this forum and dug up a comment by walltech from a thread on the topic long ago (2007).  See below.

> It is much easier to wire an ICF with the proper tools: hot knife(supplied by your ICF supplier) and a electric chainsaw (45.00 from H-depot or Lowe's)along with the proper screw on carlon boxes after the concrete pour.

I'm all for keep it simple and cheap. 

One problem I'm having with this approach however is to exactly match the box depth to the 2.5" of the ICF styrofoam.   Does anybody know of a box available at Lowes or Home Depot with a 2.5" depth?   Most of the boxes that I am finding in these stores are almost 3" deep.  They are designed to be used with 2x4's.

I found this shallow box...

http://www.homedepot.com/h_d1/N-5yc1v/R-100404058/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=electrical+box&storeId=10051#specifications

It is 1.25 inches deep.      I could use the shallow box and insert a 1 inch piece of wood behind it for a total of 2.5".   If I don't find a box that is exactly 2.5" deep I think I'll have to resort to this shallow box solution.

Another problem I'm having is figuring out how to attach the box to the concrete.  I have some small short tapcon screws.  If I attach the boxes using the small tapcons onto the concrete in the back is some inspector going to get spasticated?

You need the 3" deep box to account for the drywall. Avoid anything smaller because of box fill volumes. A 3" deep box is only 18 cu in which can only hold 2 12-2/with ground romex.
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As jeepster said, use the 3" box. Actually I think they're 2 15/16" deep. Get the ones with the mounting tab to nail to the front of the stud, and put the box next to a web and fasten with a screw into the web. This one: Carlon box

The only boxes I fastened to the concrete were round fixture boxes. They have recessed mounting holes so the screw heads don't project into the box volume proper. Code doesn't like metal inside the volume of a plastic box. Carlon round box

I've been using some of these boxes.
http://www.ipexamerica.com/Content/Products/Product.aspx?ProductId=109&SubMarketId=17&MarketSegmentId=5

The side screw 3" boxes are fine for single gang boxes in my experience. I like the metal mud ring boxes for two gang and above. You can mount them flat to the concrete. The plastic boxes tend to warp with the Romex stuffed in them. This normally comes up during the final trim out when the customer wants all the boxes straight and plugs and switches uniform. Wait until you get a picky customer and you will find out. Electric chainsaws are much faster and better in my experience. The time and fumes of the hot knife are way to nasty. The chainsaw will leave more mess but its way faster.

Posted By Roundeye on 06 Nov 2012 12:20 PM
I've been using some of these boxes.
http://www.ipexamerica.com/Content/Products/Product.aspx?ProductId=109&SubMarketId=17&MarketSegmentId=5

The above boxes look like a pretty good product. Anyone here use them?

They work great - fast easy and provide a strong connection to EPS.

When Romex is laid inside of the foam, how does one prevent someone from running a drywall screw or picture nail through it? With wood you use steel plates and the Romex sits outside of the nail/screw area. With ICF/EPS foam, I can see that becoming a problem with running a nail or screw through the Romex fairly easily.

If you push the Romex all the way down into the slot, it is deep enough to avoid normal length screws. Code is 1-1/4", IIRC. I've seen it held in place with chunks of foam, or a foam gun.

Anyone got a ballpark cost on the Ipex boxes?

The Ipex boxes weren't but about buck 50 or so. Little expensive but easy to install given the other option of drilling and setting a metal box.

My contractor said he just glues boxes in with foam, but I like those Ipex boxes. They sound reasonable- as long as they're not like $10 or something, I might use them.

Posted By jdebree on 30 Nov 2012 05:22 PM
My contractor said he just glues boxes in with foam, but I like those Ipex boxes. They sound reasonable- as long as they're not like $10 or something, I might use them.

Cost: $3.75 to $6.75 per box. Wind-lock. 800-872-5625.

according to this site:

http://www.builderonline.com/products/wind-lock-inexo-electrical-boxes.aspx

In my case with about 150 boxes they would have cost me roughly $300 more than the boxes I used.

Posted By Roundeye on 30 Nov 2012 12:44 PM
The Ipex boxes weren't but about buck 50 or so. Little expensive but easy to install given the other option of drilling and setting a metal box.

No need to do very much drilling and setting, unless you're committed to metal boxes. See the comments earlier in this thread.

Actually, the Wind-Lock pricing is lower than others I found. One site was $800-$1600 per hundred, or $8 to $16 each. That's a little ridiculous. Since I'm building my own place, labor isn't as much of a factor. I like the idea of the ones with a mounting flange on one side to attach to the web. A shot of foam would further secure it. I really dislike wobbly outlets. The bigger multiple gang boxes I'll just tapcon to the concrete.

It was cheaper for me to go factory direct. FYI

Thanks, Roundeye. I'll check with them on price. Hopefully I don't have to buy them in bulk, since I'm only doing one house. On a related note, I dug out my old Wen electric chainsaw, and it still runs! The bar is shot, but I found that the 10" bar and chain from my pole saw fits well. I'm going to attach a depth bracket to the bar to keep the chain from hitting the concrete. I need to cut the plastic web in various places, so I'd like to save the chain. Some clever individual needs to make a purpose-built mini saw with like a 3" bar and an adjustable depth, plus a vacuum attachment for ICF. Holding on to a regular electric chainsaw is awkward for slotting.

How does one install electrical outlets on the OUTSIDE of an ICF wall? Where would one make the penetration on the wall?

On a similar note, how would one run Cat5 in the walls. How about Cat5 to the exterior in case one wants to run CCTV with PoE?

I'll be installing several outdoor outlets. Code requires at least two. In the basement walls, I put PVC pipe in a several places for wiring and plumbing pre-pour. On the main floor, I'll go up and over the top plate, then channel the foam to bring the wiring down to the box. If I knew the exact locations, I would have cast a PVC pipe in place, but my design is evolving some as I build. I could also drill- I might try it to see if its less work than channeling the foam. I'm assuming the boxes install the same way as indoors. With the added thickness of the drainage plane and the siding, there should be plenty of depth available. It's interesting to note that the boxes on my current home aren't sealed or caulked in any way, and they weren't GFIC until I replaced them. The rain has never affected them.