# Boxes part way in block wall



## Dennis Alwon (May 9, 2009)

Is the block hollow? If so you can bust the block out big enough and deep enough for a 4" sq. box with brackets. the furring strip can hold the box in place.











OR

One of these for mc cable if that is what you have


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## 3xdad (Jan 25, 2011)

Code wise, you'll just run into the "listed for use" stuff. i would not rely on silicone etc. for mounting. You may get away with mortaring a 4 square as where i can't over here.

Can you use the shallow 4 square (1 1/2") with mud ring?


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## joebanana (Dec 21, 2010)

There is no code section on "chipping" or "busting" any finished surface. Being an exterior wall (load bearing)I don't think the inspector will go for "glue in boxes" Since the drywallers beat you to it, it sucks being you right now. If you had your stuff nailed to the block before they showed up with the furring, it would be their problem.(woulda, shoulda, coulda) I suppose you can't go surface?


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## freeagnt54 (Aug 6, 2008)

1.25" 4 square anchored to the block with 1/4" mudrings.


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## telsa (May 22, 2015)

freeagnt54 said:


> 1.25" 4 square anchored to the block with 1/4" mudrings.



Plan B:

4-11/16" square @ 1.25" deep with 1/4" mud ring.

Let the mudders deal with the roughcut.

Use a Fein Multi-Master for perfect cutting in.


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## papaotis (Jun 8, 2013)

did everyone not read the OP? it says existing firring and drywall. been there a while. and no, there isnt a problem busting a hole the block to fit a box into as long the hole isnt big enough to jepordize the structure. (not gonna happen in your case) as long as you have something to support the box, go for it!


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## freeagnt54 (Aug 6, 2008)

papaotis said:


> did everyone not read the OP? it says existing firring and drywall. been there a while. and no, there isnt a problem busting a hole the block to fit a box into as long the hole isnt big enough to jepordize the structure. (not gonna happen in your case) as long as you have something to support the box, go for it!



If he wants to screw around all day trying to bust out block through a tiny cut-in-box hole, that's fine, hes not on my crew.

Or he could cut a 4x4" hole, fish wire down, connect m/c, anchor box, mud ring and move to the next one.


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## donaldelectrician (Sep 30, 2010)

psd7.3 said:


> I've spent most of my morning reading through code book to try and find answers to my question but have not found anything really specific to my question.
> I have a build out I am doing in an existing shopping center, their is an exterior wall that is block that has 1" furring strips and 1/2 drywall. My idea was to chip the block face down a 1/4-1/2" to fit my box in the wall, mount a 4x4" to the block and bring my MC into that however I know trying to chip the block will result in in busting out. My new idea is to bust the block out around the block and mount a 2x4" flat to that wall and mount my nail on 4 inch square boxes to that and then siliconing or mortaring around the box, where at in the NEC could I find a article relating to this matter.
> Thanks for all your replies!




I am not sure What ART in the NEC you are looking for ?

Ex Block Walls are not considered Same Loco as interior block walls ...

We did not Smash Holes in Block Wall ... We used a small grinder with the 

Diamond Mason wheel ... Set Box ... set ring .



Don


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## papaotis (Jun 8, 2013)

rereading the OP what is going in the box? 1" furring and 1/2" drywall make 1&1/2" depth, a normal every day box wether 2x4 or 4x4


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## psd7.3 (Jul 2, 2010)




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## psd7.3 (Jul 2, 2010)

That is what i came up with, the furring strip was only 3/4 inch so i had to remove about 1/4" of the block surface, I appreciate all of your ideas!


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## psd7.3 (Jul 2, 2010)

Dont mind the crooked drywall cuts, laid off landscapers dont always make great GC helpers &#55357;&#56842;


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## donaldelectrician (Sep 30, 2010)

psd7.3 said:


> View attachment 73169





OMG .... What a " Patch " Job .....


You got to teach him how to cut rock so it is patch easy ...

You know the , Blow out patches ... cut on studs flap patch ... side ways flap 
patch .... thumb cuts ... ect......



Don


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## telsa (May 22, 2015)

psd7.3 said:


> View attachment 73169


That is gruesome.

Did you EVER hear of the pumpkin cut ?



:whistling2:


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## telsa (May 22, 2015)

psd7.3 said:


> View attachment 73169


With that level of 'detail'.... the rockers should start from scratch.

:laughing::laughing::laughing::laughing::laughing:


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## frenchelectrican (Mar 15, 2007)

psd7.3 said:


> View attachment 73169


I am see something is missing is the conductors ..

how ya going get that in that mc cable ??


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## splatz (May 23, 2015)

papaotis said:


> rereading the OP what is going in the box? 1" furring and 1/2" drywall make 1&1/2" depth, a normal every day box wether 2x4 or 4x4


For a nice finished appearance the box has to be entirely in the furring strip, the mud ring in the drywall. 

Before I'd start chipping up the block, I'd explain to the customer that the furring strips are sized incorrectly for the acceptable wiring methods / boxes available, and use a wiremold extension. That way you don't need a mud ring. 








I usually try to get approval for this kind of thing before, some prefer seeking forgiveness after.


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## Southeast Power (Jan 18, 2009)

psd7.3 said:


> I've spent most of my morning reading through code book to try and find answers to my question but have not found anything really specific to my question.
> I have a build out I am doing in an existing shopping center, their is an exterior wall that is block that has 1" furring strips and 1/2 drywall. My idea was to chip the block face down a 1/4-1/2" to fit my box in the wall, mount a 4x4" to the block and bring my MC into that however I know trying to chip the block will result in in busting out. My new idea is to bust the block out around the block and mount a 2x4" flat to that wall and mount my nail on 4 inch square boxes to that and then siliconing or mortaring around the box, where at in the NEC could I find a article relating to this matter.
> Thanks for all your replies!


Everything here is CBS. I've smashed holes in concrete blocks for decades and usually we screw a furring strip on each side and the GC either patches the hole or it gets blasted with foam buy us unless someone wants to play with mud.
And
I assure you, our south Florida building codes are very, very strict.


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## JohnJ65 (May 8, 2008)

Cut a large opening for your 4x4x1-1/2" box, fasten it to the block, install a 1/2'' mud ring and have the general slap another sheet of 1/2" drywall over the entire wall. It would probably be faster for you and the drywall contractor in the end.


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## Southeast Power (Jan 18, 2009)

JohnJ65 said:


> Cut a large opening for your 4x4x1-1/2" box, fasten it to the block, install a 1/2'' mud ring and have the general slap another sheet of 1/2" drywall over the entire wall. It would probably be faster for you and the drywall contractor in the end.


Here, patching those holes is part of the insulation inspection.


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## telsa (May 22, 2015)

psd7.3 said:


> Dont mind the crooked drywall cuts, laid off landscapers dont always make great GC helpers ��



The GC's man made those cuts ? :thumbup:

Lucky you.

:laughing::laughing::laughing:


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## telsa (May 22, 2015)

BTW, if you don't have a Fein Multi-Master -- the next best thing is a cordless panel saw. Light and lower in power are pluses.

You can plunge cut -- and control your depth... even cut bevels.

As for pumpkin cuts: jump to 3:15


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## zac (May 11, 2009)

Like the pumpkin cuts, thanks 

Sent from my SGH-M919 using Tapatalk


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## freeagnt54 (Aug 6, 2008)

That sheet rock guy is going to be cursing your name.


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## RePhase277 (Feb 5, 2008)

freeagnt54 said:


> 1.25" 4 square anchored to the block with 1/4" mudrings.


Yes. Chisel the sheetrock out and mount the boxes straight to the block face. You can order device plates in 2 gang size but cover just one device.


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## zac (May 11, 2009)

InPhase277 said:


> Yes. Chisel the sheetrock out and mount the boxes straight to the block face. You can order device plates in 2 gang size but cover just one device.


Fo Chisel 

Sent from my SGH-M919 using Tapatalk


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## RePhase277 (Feb 5, 2008)

telsa said:


> BTW, if you don't have a Fein Multi-Master -- the next best thing is a cordless panel saw. Light and lower in power are pluses.
> 
> You can plunge cut -- and control your depth... even cut bevels.
> 
> ...


That guy knows d!ck about terminology... firewall, I beams, plywood, 110...


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## LanternElectric (Jun 18, 2015)

*So what happens when...?*

It will make for a some what dangerous install, I wish you the very best of luck.Also hope your GL covers faulty work.


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