# Cutting electrical boxes in block



## Rjthomas111 (Apr 7, 2013)

I have a project starting that the architect wants the electrical boxes to be in the center of the block rather than at bottom. Has anyone else seen this before? If so, what type of router tool works best?


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## jlsconstruction (Apr 26, 2011)

More info please. What actually are you doing. Block as in cmu's?

I'm guessing 4.5" grinder


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## Rjthomas111 (Apr 7, 2013)

jlsconstruction said:


> More info please. What actually are you doing. Block as in cmu's?
> 
> I'm guessing 4.5" grinder


It's ground face cmu


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## Rjthomas111 (Apr 7, 2013)

Rjthomas111 said:


> It's ground face cmu


Are you a mason contractor?


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## Inner10 (Mar 12, 2009)

Rjthomas111 said:


> Are you a mason contractor?


Asking yourself?


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## Rjthomas111 (Apr 7, 2013)

Inner10 said:


> Asking yourself?


Just got on board here....but it appears i did lol


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## NJ Brickie (Jan 31, 2009)

Architect should not dictate where electric boxes are located. Electrical code should. 

I have run into this issue before and with enough arguing the boxes usually just get lowered. 

But the solution to your problem is to cut a one holer then cut the box opening at the desired height on the end of the block.


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## Rjthomas111 (Apr 7, 2013)

Rjthomas111 said:


> It's ground face cmu


The electrical box measures 2 1/4" by 3" so angle grinder won't work. Some type of router would have to be used.


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## Rjthomas111 (Apr 7, 2013)

NJ Brickie said:


> Architect should not dictate where electric boxes are located. Electrical code should.
> 
> I have run into this issue before and with enough arguing the boxes usually just get lowered.
> 
> But the solution to your problem is to cut a one holer then cut the box opening at the desired height on the end of the block.


He wants it in center of web....it's visual performing arts building, has different specs...have you did this before? These block cost around $9 each so want to find best solution before wasting units.


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## Inner10 (Mar 12, 2009)

Rjthomas111 said:


> The electrical box measures 2 1/4" by 3" so angle grinder won't work. Some type of router would have to be used.


Grinder and a cold chisle.


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## NJ Brickie (Jan 31, 2009)

Center of web?? The boxes need to be located in the center of the block in both height and width? Why? Just for the look of it?

Doesn't matter what the buildings purpose is, the architect does not have a say in the location of electrical devices. Electrical code determines the locations. I.E. certain height from floor, spacing, or distance from doors.

Yes I have install boxes in the center of block (top to bottom) using the method I told you. But that will not work if it needs to be centered from side to side also.


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## 480sparky (Feb 1, 2009)

NJ Brickie said:


> Architect should not dictate where electric boxes are located. Electrical code should. .........


Other than ADA requirements, they don't. :no:



NJ Brickie said:


> ...... Electrical code determines the locations. I.E. certain height from floor.......... or distance from doors........


Perhaps you could enlighten us where in the Electrical code that is.....


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## NJ Brickie (Jan 31, 2009)

Inner10 said:


> Grinder and a cold chisle.


That will not work if it needs to be centered from right to left also. The center web of the block will be in the way. Unless they happen to be Ivany block. 

Also you will most likely break a few for every one you are successful with.


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## NJ Brickie (Jan 31, 2009)

480sparky said:


> Other than ADA requirements, they don't. :no:
> 
> 
> 
> Perhaps you could enlighten us where in the Electrical code that is.....


Well I not an electrician. So I will not be doing any "enlightening". ADA requirements are what I was referring too. An architect has no standing on changing ADA requirements.


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## jlsconstruction (Apr 26, 2011)

I'll make a video tomorrow of how you can do it with a grinder. 

To the op how deep are the boxes.


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## Rjthomas111 (Apr 7, 2013)

NJ Brickie said:


> Center of web?? The boxes need to be located in the center of the block in both height and width? Why? Just for the look of it?
> 
> Doesn't matter what the buildings purpose is, the architect does not have a say in the location of electrical devices. Electrical code determines the locations. I.E. certain height from floor, spacing, or distance from doors.
> 
> Yes I have install boxes in the center of block (top to bottom) using the method I told you. But that will not work if it needs to be centered from side to side also.


In the center of a cell........a 4" diamond blade is not going to score deep enough.....using a chisel could crack the block plus take too much time.


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## NJ Brickie (Jan 31, 2009)

jlsconstruction said:


> I'll make a video tomorrow of how you can do it with a grinder.
> 
> To the op how deep are the boxes.


Just keep in mind that these are ground face block. Can't have any over cut showing past the plate.

I can see getting them scored with a grinder. Just not being able to cut through the whole web with out having too much over cut.


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## griz (Nov 26, 2009)

Find a Granite/Stone counter top guy with a CNC machine & have him cut them for you.:thumbsup:


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## NJ Brickie (Jan 31, 2009)

Rjthomas111 said:


> In the center of a cell........a 4" diamond blade is not going to score deep enough.....using a chisel could crack the block plus take too much time.


Ok so your only restriction is the height from the floor correct? You can place them from right to left anywhere on the block?

If so just do it like I said earlier. Cut a one holer then cut the box in at the desired height on the end of the block.


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## Inner10 (Mar 12, 2009)

NJ Brickie said:


> That will not work if it needs to be centered from right to left also. The center web of the block will be in the way. Unless they happen to be Ivany block.
> 
> Also you will most likely break a few for every one you are successful with.


I did it for a door station recently and I'll admit it took me quite a while. I drew the rectangle, went as deep as possible with a turbo blade on the grinder, drilled a couple holes where the webbing was and tapped it out with a hammer and chisel.

If a two bit wire jockey could figure it out I think a seasoned brickie could handle it.


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## Rjthomas111 (Apr 7, 2013)

NJ Brickie said:


> Ok so your only restriction is the height from the floor correct? You can place them from right to left anywhere on the block?
> 
> If so just do it like I said earlier. Cut a one holer then cut the box in at the desired height on the end of the block.


They have to be centered top to bottom , left right in center of cell....can't move them!!


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## NJ Brickie (Jan 31, 2009)

Inner10 said:


> I did it for a door station recently and I'll admit it took me quite a while. I drew the rectangle, went as deep as possible with a turbo blade on the grinder, drilled a couple holes where the webbing was and tapped it out with a hammer and chisel.
> 
> If a two bit wire jockey could figure it out I think a seasoned brickie could handle it.


Can it be done? Sure. A lot of things can be done. Is that practical? No. No one is doing that for an entire building. 

You are also talking about installed block. Totally different situation.


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## jlsconstruction (Apr 26, 2011)

griz said:


> Find a Granite/Stone counter top guy with a CNC machine & have him cut them for you.:thumbsup:


How come you're the only one that thinks outside the box. I never think about stuff like that for some reason. 

To the op how many holes are we talking


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## NJ Brickie (Jan 31, 2009)

Rjthomas111 said:


> They have to be centered top to bottom , left right in center of cell....can't move them!!


Well I hope that was in the specs then and you caught that before your bid. Score them with a grinder, drill holes and knock them out with a chisel.


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## jlsconstruction (Apr 26, 2011)

NJ Brickie said:


> You are also talking about installed block. Totally different situation.


When did it say the block are installed?


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## NJ Brickie (Jan 31, 2009)

jlsconstruction said:


> When did it say the block are installed?


I quoted inner10.


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## jlsconstruction (Apr 26, 2011)

NJ Brickie said:


> I quoted inner10.


I'm way to tired to keep up with this conversation.


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## Inner10 (Mar 12, 2009)

NJ Brickie said:


> Can it be done? Sure. A lot of things can be done. Is that practical? No. No one is doing that for an entire building.
> 
> You are also talking about installed block. Totally different situation.


Then install the block first of that makes it easier....

Does it have to be a rectangular box? Have them use an oct box and core a round hole.


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## Dustincoc (Sep 14, 2011)

What about drilling out the bulk of the hole, then chipping out the rest with a chisel.


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## brickhook (May 8, 2012)

I'm guessing my 2 cents might not matter here, but...I've done churches, hospitals, schools, gyms, community centers, etc. I've always put switches in the bottom of the 6th coarse which makes the bottom of the box at 40", or some archies might want them in the top of the 6th coarse which puts the box at 44".

Recepticles, switches, and fire alarms are all on different levels...but, I've always cut them in either in the bottom or the top of the block. And that takes enough time. Who ever is asking you to cut them in the center isn't being very logical, or they apparently haven't done many block buildings. 

I'm not saying they're wrong and I'm right, I'm just saying they're wanting you to do this different. You can lay 40 block by the time you route, chisel, and cut a hole in the center of a block. So if this is a commercial job, that's going to be equivalent to $120 a box!


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## dbrons (Apr 12, 2010)

you could make a slab out of it so you could finish your cut from the back side.
Dave


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## stuart45 (Oct 7, 2009)

The closest machine I've seen to what you need is one of these.
http://www.youtube.com/watch?v=OSVjn0PF4x8
You would still need to do what NJBrickie said about scoring the outline with a diamond blade as these are normally used when the blockwork is plastered, as with the chasing machines for the wiring in the walls.


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## concretemasonry (Dec 1, 2006)

stuart - 

I have seen similar tools for both square and rectangular boxes.

NJBrickie - You might be interested that in many area difference shapes, core configurations (1/2, 1, 2, 3, cores) and web locations/configurations are available in various different block thicknesses. - It is a big world with different standards.

For all architectural CMUs,- ground face, polished, sandblasted, split and colored, the proper specific block shapes must be determined before the block are made or processed. That is necessary for matching on critical architectural structures, but not is so critical where matching for external big projects is usually limited to matching stretchers, 1/2s, corners, jambs and bond beams.


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## JBM (Mar 31, 2011)

Drill a bunch of holes around the outline done by the grinder if you have to put it in the middle of the block. Leave a 1/2" around the box or it wont fit.


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## NJ Brickie (Jan 31, 2009)

concretemasonry said:


> NJBrickie - You might be interested that in many area difference shapes, core configurations (1/2, 1, 2, 3, cores) and web locations/configurations are available in various different block thicknesses. - It is a big world with different standards.


What are you talking about Dick? I am well aware of different types of block. If you read my posts on this thread you would have seen that I mentioned the possibility of these block being Ivany block.


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## NJ Brickie (Jan 31, 2009)

Inner10 said:


> Then install the block first of that makes it easier....
> 
> Does it have to be a rectangular box? Have them use an oct box and core a round hole.


Installing the block and letting it sit over night everywhere you need a box is not practical either.


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## NJ Brickie (Jan 31, 2009)

griz said:


> Find a Granite/Stone counter top guy with a CNC machine & have him cut them for you.:thumbsup:


If every box cut is the same this could work. But that is usually not the case. Even in this situation, the combinations seem to be too many to make this idea work. If you need a single gang on the left side of the block and a double gang on the right, or two double gangs, or a single gang on the front right side and a double gang on the back left side.


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## artisanstone (Nov 27, 2007)

I would try a holesaw sized to the smaller dimension. Make two holes, then cleanup with a grinder. 

Or renegotiate this whole deal.


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## dbrons (Apr 12, 2010)

>>Even in this situation, the combinations seem to be too many to make this idea work. <<
Agree. Back when I was working in the union this sort of thing would be handled by our foreman. He'd probably convince them to OK box placement in the bottom of block as usual.

But one thing I do recall, yeas ago on one school. They wanted the boxes up there because they said when at the bottom the cover plate extends down into the mortar joint. The electrician said the kids could be hurt if they ran their finger down the wall while walking the halls.

It was a pain and I think we cut them in and then saved a strip of the cutout to replace as a plug underneath the box . These were standard block and got painted so we would have just rubbed the small joint around the plug. wouldn't work with ground face.


Dave


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## artisanstone (Nov 27, 2007)

More ideas...

For cleanup after the holesaw:
-Diamond chainsaw, blade width on mine is 3 1/2"
-Die grinder, body is smaller than electric grinder
-Carbide blade for sawzall. I bought some years ago, but have never tried them out. Don't know how effective.


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## stacker (Jan 31, 2006)

i have a carbide for my sawzall.works great to cut block.
drill holes large enough for the blade and follow you line for a tight fit.


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## CJKarl (Nov 21, 2006)

NJ Brickie said:


> Well I hope that was in the specs then and you caught that before your bid. Score them with a grinder, drill holes and knock them out with a chisel.


I do stuff like this all the time. Finish block, finish bluestone. Need to have skilled craftspeople doing it. 4" grinder cut as deep as you can, score, cut diagonal. Tap out with a small sharp chisel.
Pay me and I'll come out and do it for you. :clap:


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## masonkable (Apr 8, 2013)

I have to add to the ideas here. With regards to any style block from burnished to a fused glazed tile face, I have cut many rectangle holes; first I outline the box or whatever needs to be inserted, then by using a diamond drill bit 3/16" in size hammer drill multiple holes all the way around the outline. The piece will obviously fall out, you will have numerous small semi-circular holes to deal with. Though after sparky inserts the box you should only have a very minimum of semi-circular holes showing, plus dont forget that there will be a switch plate our outlet plate that will cover any small defects of the drilling. I would say it should take about 5-7 minutes per hole to do. I have done multiples of these on commercial projects in the past. And if it is also a architectual thing that they are needed in the middle of the face of the unit, then oh well, thats what needs to be done.


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## sleeper (Sep 17, 2012)

I’m not a Mason, but I’ve had to do this a number of times as an electrician. 
I tried a lot of ways, but I always ended up drilling holes in each corner and using a small grinder to cut between the holes. The round grinder will not cut all the way through, but at least gives you a straight edge and then I used a chisel to break it up and clean the sides.


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## Rockmonster (Nov 15, 2007)

Although it seems like an odd request by the architect, nothing surprises me nowadays. But this might be just what the doctor ordered;http://youtube.com/watch?v=7hfyyJqnNk0

I don't envy you with groundface........


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## concretemasonry (Dec 1, 2006)

Brick -

Apparently you are a small customer for the limited block producers in your area. The Ivany is an old, archaic (40 years old) they was made for a different purposes.

Few contractors buy enough block to be able to get specials made and will not pay the price. The good supplier of architectural block spuuplier (especially burnished and colored) can get the block from a supplier or make them and finish them with cut-outs to mason contractor.

I have seen colored 8" burnish/ground block made with one flush en and one with "ears", 2 cores that were different sixes and one had a solid bottom. - It was worth it for the project and fortunately, the architect had it on the architectural and acoustic drawings for a concert hall.


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## NJ Brickie (Jan 31, 2009)

CJKarl said:


> I do stuff like this all the time. Finish block, finish bluestone. Need to have skilled craftspeople doing it. 4" grinder cut as deep as you can, score, cut diagonal. Tap out with a small sharp chisel.
> Pay me and I'll come out and do it for you. :clap:


That's the whole point. "Pay me". What the architect is asking for is not considered normal means or methods. Soooo like I said, sure it can be done. But it had better been called out in the specs. It hardly takes "skilled craftspeople" to cut boxes in CMU. But it takes a lot of extra time (money) to cut it the way the architect is asking for.


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## NJ Brickie (Jan 31, 2009)

concretemasonry said:


> Brick -
> 
> Apparently you are a small customer for the limited block producers in your area. The Ivany is an old, archaic (40 years old) they was made for a different purposes.
> 
> ...



I'm not here to have a pissing contest with you or anyone else. I am not a customer at all. I work for a large masonry company out of Philadelphia. We have had specialty block made for various projects, including stadiums and schools. But this still has nothing to do with the OP question. Going under the assumption that he is using a standard CMU. He needs the center of his boxes to be 3 5/8" from the end and 3 5/8" up from the bottom. How does the type of block he is using change the fact this can not be done using normal means and methods?


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## Nac (Apr 16, 2006)

NJ Brickie said:


> That's the whole point. "Pay me". What the architect is asking for is not considered normal means or methods. Soooo like I said, sure it can be done. But it had better been called out in the specs. It hardly takes "skilled craftspeople" to cut boxes in CMU. But it takes a lot of extra time (money) to cut it the way the architect is asking for.


If it is not called out in the spec or a detail in the drawing it has change order written all over it. I agree it can be done but at an extra cost. Never mind all the bends you have to put in the conduit above the box to miss all the webs or you are going to have to cut the center web and close pin all the other cmu above.


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## Nac (Apr 16, 2006)

concretemasonry said:


> Brick -
> 
> Apparently you are a small customer for the limited block producers in your area. The Ivany is an old, archaic (40 years old) they was made for a different purposes.
> 
> ...


Not that I want to get evolved but I am from the area and we have quite a few large cmu suppliers manufactures in the area. Clayton Anchor Block (Old Castle) and they will make anything you want if your order in advance and want to pay to tool up. And Ivony block are a usually a stock item around here but it is for a retaining wall. In our area two hole block is standard cmu.


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