I left a 2" conduit in the wall before pouring concrete.   The plans called for the electric panel to be outside the house at the bottom of the wall.    The house is in a flood zone so the bottom of the wall is 4 feet above grade.   That means for every circuit a wire goes into the house and up the wall.     Up the wall means through the styrofoam of my ICF walls.   So I carved a 2 inch wide canal in the styrofoam up the wall.   I need about a dozen 10 guage romex wires to pass through this portal.   In the 2 inch canal they will be bundled.   Then I found out that supposedly bundling is a no-no according to code for distances of 24" or more.    Ooops!   I suppose I could spray some great-stuff in the hole to cover it up.   The carved out hole is fix-able.   How do I pass lots of romex through a wall without bundling them up?

I bought a whole carton of the 1-gang 22 cu. in. electrical boxes.   Supposedly ICF walls are 2.5 inches thick.   Integraspec blocks are and are not.  Their walls have groves in them that allow for 2.5" in some places and 2.25" in others.   I'm going to have to return them and replace them with 18 cu. in. boxes and try to mount them using a concrete screw to the back wall.   Cannot use the side mount to attach them to a web.

I have a few boxes of 8", 6" and 4" Integraspec webs.   I am going to put them on craigslist free.  For the taking if anybody wants them.  I am in SoCal in the Los Angeles area.   My email is jactkca at gmail.com

Can you spread them out once they emerge from the wall? Going through the wall will be less than 24", then split them up into a number of small channels (I know, it won't be as pretty). You can bundle wires, but they must be derated, depending on how many you bundle.

Don't forget to leave enough of your electric boxes sticking out from the ICF to allow for your drywall (or whatever you use). I think you need to be within 1/8" of the finished surface. I mounted most of my boxes alongside a web, and used boxes with a flange on one side, which I screwed to the web. I also shot foam in behind the box as I set it in place, and they are very solid. I know some builders don't fasten at all, but just use foam. I worry that the foam could break down and loosen up over the years. Why can't you attach to the webs?

which I screwed to the web

grumble grumble

I attached a 1" piece of plywood to the ICF outside to the ICF webs and then the panel will attach to that.   The wood screws attach to the webs.   Actually they don't but who am I to argue?   Cross your fingers and hope you have a good connection and that the 200 AMP panel doesn't fall off.   In theory when you attach a piece of wood or what not to an ICF block with a screw it connects and bonds.  In practice sometimes it does sometimes it doesn't.    It depends on whether and how you hit the web in the styrofoam.   Normally this doesn't matter.  With a 200 AMP panel it could be trouble.

Posted By jdebree on 23 Sep 2013 06:53 PM
then split them up into a number of small channels

what does the code say for distancing?   1/2"  ? 1" ? more? less?

Posted By jacktca on 23 Sep 2013 05:12 PM
I'm going to have to return them and replace them with 18 cu. in. boxes and try to mount them using a concrete screw to the back wall.   Cannot use the side mount to attach them to a web.

I suggest you quickly spend the $60+ to buy a CD copy of the latest IRC. It has the pertinent parts of the NEC in it. For issues like bundling it is your friend.

Now, double check, or even triple check, the idea of the screws to hold the boxes in place. IIRC, metal screws inside plastic boxes are verboten, except in recesses made for that purpose. Are you absolutely sure you can't use the 22" boxes? As I recall you can only terminate three 12 gauge cables in an 18" box. 22 will accommodate 4. Only 3 in a box will be a serious constraint in your wiring scheme.

Out of curiosity, why did you not mount the meter outside and run a service conduit through the wall to the panel on the inside? That's what I did, and then built a chase to run wires up to the ceiling. This was in the garage so the protrusion of the chase from the wall was a minimal aesthetic issue. In my case the service conduit from underground to the meter was buried in the foam and the meter set into the foam. Idaho Power guys were not happy. They want the service conduit to be exposed outside of the wall surface to prevent people tapping into it and stealing electricity. I plead lack of clarity of power company guidelines and the fact the wall was concrete so tapping into the conduit would be a near impossible task. They relented and pulled the wires. This was on the street side of the house so I didn't want the ugly conduit showing.

Posted By dmaceld on 23 Sep 2013 08:41 PM

Posted By jacktca on 23 Sep 2013 05:12 PM
I'm going to have to return them and replace them with 18 cu. in. boxes and try to mount them using a concrete screw to the back wall.   Cannot use the side mount to attach them to a web.

I suggest you quickly spend the $60+ to buy a CD copy of the latest IRC. It has the pertinent parts of the NEC in it. For issues like bundling it is your friend.

Now, double check, or even triple check, the idea of the screws to hold the boxes in place. IIRC, metal screws inside plastic boxes are verboten, except in recesses made for that purpose. Are you absolutely sure you can't use the 22" boxes? As I recall you can only terminate three 12 gauge cables in an 18" box. 22 will accommodate 4. Only 3 in a box will be a serious constraint in your wiring scheme.

Out of curiosity, why did you not mount the meter outside and run a service conduit through the wall to the panel on the inside?

you misunderstood what kind of box I was referring to
the boxes will house one receptacle

Here's a link to what I bought:

http://www.homedepot.com/p/Carlon-1-Gang-Non-Metallic-New-Work-Box-with-Bracket-B118B-UPC/100404148#.UkD6Ij9iMns

this is the 22 cubic inch version
the boxes are 2.5" deep, exactly
they leave 1/2" for drywall past the bracket
for a total depth of 2.91"

I was thinking of using a 18 cubic inch version without the bracket instead
the total depth of this type of box is 2.75"
and just using a small concrete screw to attach it to the wall  smack in the back
that would come out to 2.25" for integraspec foam and 1/2" for drywall

if I cannot use a metal screw to connect this kind of box to the concrete in the back then I am in a pickle
the ones with a bracket stick out by 1/4 inch = 0.25" in my Integraspec blocks
the concrete starts at 2.25" with Integraspec
If I locate these next to a web and use the holes in the brackets for screws the 1/4" extra space caves in and mangles the angle of the outlet
it looks awful

Posted By jacktca on 23 Sep 2013 10:38 PM

if I cannot use a metal screw to connect this kind of box to the concrete in the back then I am in a pickle
the ones with a bracket stick out by 1/4 inch = 0.25" in my Integraspec blocks
the concrete starts at 2.25" with Integraspec
If I locate these next to a web and use the holes in the brackets for screws the 1/4" extra space caves in and mangles the angle of the outlet
it looks awful

Here's the paragraph I'm referring to from the 2006 IRC. It's more than likely still the same.

E3806.8.2.1 Nails and screws. Nails and screws, where used as a fastening means, shall be attached by using brackets on the outside of the enclosure, or they shall pass through the interior within 1/4 inch (6.4 mm) of the back or ends of the enclosure. Screws shall not be permitted to pass through the box except where exposed threads in the box are protected by an approved means to avoid abrasion of conductor insulation.

The intent is to have no sharp metal edges inside the box that can abrade the wires. Screw heads are not specifically mentioned but they can have sharp edges. You need to talk to your electrical inspector to see if he'll allow you to use screws. I tried a Ramset fastener but it was a disaster. Either wouldn't go in deep enough or tore up the back of the box. You just have to be careful and not run the screws very tight. I mounted my boxes to webs using the side brackets. If the boxes aren't angled very much it's really not much of a problem because the ears on the devices will bear on the drywall and hold them straight.

As to fill the code says a #12 wire will be counted as 2.25 cu in, and the device double that. So for an 18 in box you have 4.5 cu in for the receptacle or switch, and 3 x 2.25 for each cable coming in (2 conductors + ground). Two cables is 6 x 2.25 = 13.5 + a device at 4.5 = 18.0. That means you can have one cable coming in and one going out. That's the usual case for receptacles, but light switches often will have power cable coming in, and power going to the next switch and one going to the light. That won't fit in an 18 in box per code. You can physically cram more into a box than the code permits, but the inspector won't buy it.

I used Fox Blocks, which are 2-5/8" thick foam. I found singles that worked well, but the 3-gang light switches are a little shallow, so I put a spacer behind them so they sit even when screwed to the web. Some plastic boxes have screw bosses, some don't. Where a single box wasn't big enough, I used a square box (which have screw bosses) and a mud ring. ICF does throw some challenges when it comes to wiring, and different systems have different problems. Some of my 3 gang switch boxes have so many wires I had to put a junction box in the attic to cut down on crowding in the switch box itself. You may have to re-configure some wiring so that the more crowded boxes are on interior walls where you can use a deeper box. I guess that's part of the reason why most people hire an electrician, but that wasn't in my budget.

> or they shall pass through the interior within 1/4 inch (6.4 mm) of the back

cool that's the plan
to connect to the back

I see this done with metal boxes all the time.  They have holes for screws in the back and no brackets on the side to attach them to anything. 

> I used Fox Blocks, which are 2-5/8" thick foam
> I put a spacer behind them so they sit even

it doesn't hurt to have too much
it hurts to have too little

I double checked Integraspec's website.  Specs say 2.5" of foam. 

Here's a link to an illustration of the crux of the problem.  I suppose you could call it a benefit if you announced it to people...

http://www.forconstructionpros.com/product/10564211/phil-insul-corp-integraspec-integrabuck

Integraspec has groves that allow for bucks to be inserted at the ends.  The groves also allow the concrete to bond well and integrate with the blocks.   Only problem is that where the concrete flows into the grove there is 2.25" of styrofoam.  Where it doesn't there is 2.5".    When you insert outlet box bracket it sticks out into the air 0.25 inch.   When you screw it into the web the outlet box bracket mangles the angle.   Instead of being 90 degrees perpendicular with the wall it is about 80-85 degrees.

I'm having trouble picturing it- is the mounting bracket parallel to the wall? If the box is 2.75, the bracket should be about 2.25. Or are you using a box with a side bracket? The plastic boxes I used have a bracket that is parallel to the wall and the face of the box, but set back 1/2" for the drywall thickness. They also make boxes with adjustable brackets, but I don't know if they make them shallow enough for your application. If box size is an issue, use 4" junction boxes with a mud ring to mount the device. The plastic junction boxes I used in a couple spots did have bosses inside for screws.

Here is an 18 cu/in. It is 2-15/16, though, so even with the 1/2" for drywall, it is still 3/16 too deep.

http://www-public.tnb.com/ps/fulltilt/index.cgi?part=B118BUPC

Here is a 4" junction box you could use with a mud ring to mount your device. It is only 1-7/16, and note that it does have screw bosses. You can just gouge out your foam to clear the nail brackets, or cut them off if your inspector is OK with that.

http://www-public.tnb.com/ps/fulltilt/index.cgi?part=4S812C

Posted By jdebree on 25 Sep 2013 06:05 PM
I'm having trouble picturing it... If the box is 2.75, the bracket should be about 2.25.

Here is the link again.

http://www.homedepot.com/p/Carlon-1-Gang-Non-Metallic-New-Work-Box-with-Bracket-B118B-UPC/100404148#.UkD6Ij9iMns

Actually the box manufacturers leave 3/8 inch = 0.375 for drywall.   The specs on this box are depth: 2.91 inches.   2.91 - 0.375 = 2.535   There in lies the problem.   This would be perfect if there were 2.5" inches of styrofoam on a block.  But there isn't.     I found 18 inch deep boxes with brackets and they were 2.75 inches deep 2.75 - 0.375 = 2.375.   That would be a smaller gap, 1/8" = 0.125, but it would still mangle the angle.

The conventional 18 inch boxes without any brackets on the side are cheap $0.19 each and simple.  They are 2.75 inches deep.   I am just going to use a small concrete screw 1 1/4" inch long to connect the box to the concrete in the back.   I figure they use metal boxes so what's a little metal in the back of a box connected to concrete which is grounded anyway.   My inspector is never going to see the screws because they will be covered by the receptacles anyway.   Another alternative is to use adhesive to glue the boxes to the concrete/styrofoam in the back.  I don't like adhesive.

I don't know what the problem is with screws, but I know that they don't like 'modifications' of any kind. It might be that without a raised boss, the box may not be strong enough to not pull out of the wall. Odds are, they'll never notice (Tap-Cons are blue, as are Carlon boxes). I don't trust glue either, but I've heard of contractors using nothing but a foam gun. I use both- foam and mechanical fastening.

I know it's ridiculous- but have you tried an air chisel on the ridges? I had to make 4 of my boxes deeper (long story) and an air chisel made very quick work of it. Messy, noisy, ugly; but quick. Too late now, but it's too bad you didn't set boxes in place pre-pour. Then the depth would be perfect.

The only problem with screws is that you need a box designed for them, with the screw holes molded into the back. As jdebree noted the problem is modification, the UL certified the box without holes drilled in it, and modification voids the certification. I did get my inspector to allow me to add a hole to one box (missing conduit in a cast in place box), but I wouldn't want to try to talk him into allowing multiple modifications. The other issue I see with screws in a plastic box is the potential exists to light up the screw with power (loose connection or whatnot), on a metal box that is no issue as the box is grounded, and any screws used to attach it would also be grounded, but if you screwed a plastic box down inside the box I think you would be required to ground each screw so a loose wire would blow the breaker rather than lighting up the screw. And I know it is not likely to be a problem, but I could see the screw coming into contact with rebar, then you would have no idea as to where the power can get to.