# Concrete block wiring



## macmikeman (Jan 23, 2007)

I've done em in emt, pvc, smurf, uf and a few nm cable. Always liked how the emt ones came out best. UF and nm cannot be embedded into masonry, so you can't grout those cells.


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## telsa (May 22, 2015)

In commercial construction the same situation is resolved with furred out walls EVERY TIME.

It gets down to economic practicality. 

Stuffing plumbing runs, and all the rest, inside cinder block walls is just not worth the hassle.


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## pete87 (Oct 22, 2012)

PVC in the slab as much as possible . Tie all pipe endings so two ways to get everywhere .


Hit the block cores .


Pete


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## ampman (Apr 2, 2009)

And buy the block mason a case of beer


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## 3xdad (Jan 25, 2011)

Seems to me there would have to be some furred pluming walls, but not throughout.

If EMT is the best method, then:

i read an old thread on here about setting masonry boxes on top of the second course with 30 or 40" vertical stubs so the "blockies" can lift the next few courses over the pipe.

Is it possible to connect the boxes with horizontal runs of pipe, or is that to much of a PITA for the masons? (Although, local ammends say no, to embed EMT in concrete)


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## sbrn33 (Mar 15, 2007)

Lots of 3 foot pieces of emt and hopefully the mason is a friend. If not get an I pad because you will be sitting for hours and hours.


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## pete87 (Oct 22, 2012)

3xdad said:


> Seems to me there would have to be some furred pluming walls, but not throughout.
> 
> If EMT is the best method, then:
> 
> ...





They have not poured the slab ? Right .

Any horizontal will be in the slab .

Is there any reason PVC dose not work ?





Pete


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## 3xdad (Jan 25, 2011)

pete87 said:


> They have not poured the slab ? Right .
> 
> Any horizontal will be in the slab .
> 
> ...


Not poured yet.

Yeah, i get the PVC in the slab, but am i clear you are saying PVC in walls also?


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## pete87 (Oct 22, 2012)

3xdad said:


> Not poured yet.
> 
> Yeah, i get the PVC in the slab, but am i clear you are saying PVC in walls also?




Yea , I think PVC is a better job ... I do not like EMT where masonry is near .

Are the block men cutting the boxes ?




Pete


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## Joefixit2 (Nov 16, 2007)

Does your area have minimum insulation requirements? In my area the minimum insulation requirements give us a place for wiring ie fir outs, foam etc. They cannot build strictly with old fashioned 88s and still meet the insulation requirements as far as I know.


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## 3xdad (Jan 25, 2011)

pete87 said:


> Yea , I think PVC is a better job ... I do not like EMT where masonry is near .
> 
> Are the block men cutting the boxes ?
> 
> ...


Yeah, i would prefer to stay ahead of them with boxes and let them mortar them in. i ain't cut'n block.:no:



Joefixit2 said:


> Does your area have minimum insulation requirements? In my area the minimum insulation requirements give us a place for wiring ie fir outs, foam etc. They cannot build strictly with old fashioned 88s and still meet the insulation requirements as far as I know.


Good point. Yes, my state has enegy regs. This might be an owner/builder type thing so i will suggest he look into it.


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## cabletie (Feb 12, 2011)

Cut your conduit 30" to optimize the ten foot lengths. Cut bundles at a time. Prep with one coupling and just enough duct tape to cover the end. Don't over due the duct tape. At times you will have to reach into the the block to coupling the next piece. Like Pete said, all horizontal runs are in the slab. You can do some in the block but you won't make friends. 

Prep all boxes with connectors and square tile rings, not the rounded mud rings. Duct tape the front and be sure to get the ground screws in. You won't get the ground screws in after they mud in the boxes. 

Use any wait time to pull in strings or wire. You can have the whole place pulled while they are still setting block. 

There is one other way. It is called deck cable around here. PVC coated MC cable designed for slabs. Personally I would not go there. 

Good luck.


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## pete87 (Oct 22, 2012)

Coffee , jelly donuts , beer for the masons .





Pete


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## btharmy (Jan 17, 2009)

I chased bricked for 6 months on a school. This included the 2 gymnasiums, so yes, I have ran some pipe inside masonry walls. 3/4" PVC cut 30" long (a bundle at a time as mentioned earlier) and deep masonry boxes! Lots and lots of duct tape.
Coupling on the top of each stub so you can reach down inside the core and cut the tape out with your knife if needed. This eliminates trying to remove tape from the glued surface. Sometimes you will really be "humping" and other times the rhythm will be easier to keep up with.


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## 3xdad (Jan 25, 2011)

i'll find out today what the roof framing will be, but how do you guys terminate your pipe when it exits out top course.

In a comm. bldg. i can see landing in a j-box anywhere up above, but in a house, i'm not so sure.


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## cabletie (Feb 12, 2011)

If there is an attic I would stub it up there and change to Romex. Raco makes a 4" square box that is an extension ring for a single gang. So if you had a drop ceiling you could end your stub in a 1gang masonry box flush with the wall. Then later add the 4" square box over the 1 gang and pipe or wire to that. The nice thing about this method is that you don't have to support the 4" square on the end of a stub sticking out of the wall. 

I would not buy beer for the mason, you will need that for yourself! Running walls with the mason can get hectic. There can be a lot going on staying ahead of them. If you leave them stubs and boxes for them to put on, you may find the material on the scaffold right where you left it. Or they might put it on after they fill the conduit with cement. One guy liked to leave the duct tape on when he connected the pipe. Sometimes the screw it up un-intentionally.


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## John Valdes (May 17, 2007)

I would use EMT in the slab and in the walls. Stub right up for setting boxes. Sounds like a low income housing project with block walls inside?

Using the drawings run everything possible in the slab. Since you are hiding the conduit and boxes inside these walls, you are going to have to be there as they put up the walls.
Good masons will help you and mud in your boxes and rings so they are perfectly flush.
Tape up each box and use concrete type EMT connectors and couplings in the slab, if they still make them. 
Its not that bad as long as the block guy is on board with you.
Get him on board.


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## btharmy (Jan 17, 2009)

John Valdes said:


> I would use EMT in the slab and in the walls. Stub right up for setting boxes. Sounds like a low income housing project with block walls inside? Using the drawings run everything possible in the slab. Since you are hiding the conduit and boxes inside these walls, you are going to have to be there as they put up the walls. Good masons will help you and mud in your boxes and rings so they are perfectly flush. Tape up each box and use concrete type EMT connectors and couplings in the slab, if they still make them. Its not that bad as long as the block guy is on board with you. Get him on board.


The material and labor savings of PVC over EMT is too much to ignore. Never mind the ease of installation.


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## ampman (Apr 2, 2009)

John Valdes said:


> I would use EMT in the slab and in the walls. Stub right up for setting boxes. Sounds like a low income housing project with block walls inside?
> 
> Using the drawings run everything possible in the slab. Since you are hiding the conduit and boxes inside these walls, you are going to have to be there as they put up the walls.
> Good masons will help you and mud in your boxes and rings so they are perfectly flush.
> ...


EMT in the slab?


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## macmikeman (Jan 23, 2007)

Its his age. We came along before pvc was generally accepted in Florida. 
I haven't run emt in a slab in a long long time, but I have encountered many collapsed rusted emt runs in slabs over the years. Pvc in slabs and dirt for me, emt for the next two or three floors. It is easier to bend it plumb so the boxes sit flush both top and bottom of the switch rings to the face of the block.


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## 480sparky (Sep 20, 2007)

btharmy said:


> I chased bricked for 6 months on a school. This included the 2 gymnasiums, so yes, I have ran some pipe inside masonry walls. 3/4" PVC cut 30" long (a bundle at a time as mentioned earlier) and deep masonry boxes! Lots and lots of duct tape.
> Coupling on the top of each stub so you can reach down inside the core and cut the tape out with your knife if needed. This eliminates trying to remove tape from the glued surface. Sometimes you will really be "humping" and other times the rhythm will be easier to keep up with.


Same here.

Cut 100' bundles at 30" with a chop saw. Then reamed it all and put on couplers.

Most blocklayers will have the first course laid long before the wall goes up. This gives you a change to lay everything out and mark the first course with a grease pencil (assuming it will be covered by the concrete floor). What box, pipe size and height (in courses, not inches!) and which side of the wall. As well as which where to stub it out when they get to that point.

With a bit of planning, you can have everything prefabbed and just sitting there waiting for the blocklayers to set it in place. Then you're there just to assemble the 30" sticks as they hop up the scaffold.


And buying a dozen doughnuts once in a while doesn't hurt either.


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## 220/221 (Sep 25, 2007)

In the olden days I wired hundreds of block houses just dropping the NM down the open cells.

Of course you need to have a chase at the top, thru the bond beam and you need to be skilled at banging in handy boxes 

Now I'd go with masonry boxes and PVC stubs up thru the top plates



> how do you guys terminate your pipe when it exits out top course.


It's just a sleeve/chase. Duct tape to keep the mud out. Just push/pull the NM in/out


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## Wireless (Jan 22, 2007)

What about the blue flex? I did one job with it and way easier then PVC!


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## sburton224 (Feb 28, 2013)

This is all I've been doing for the last 11 months, I'm sick of chasing masons. PVC underground to ridged 90, changeover to EMT at grade in the block. Then stub with 30" pieces. Receptacles are all fed from underground. Data, switches, and such stubbed above ceiling. We use regular 4Sq boxes with 1 1/2" or 2" tile rings depending on the size of the block. Many of the masons will do your job for you, others however need to be watched. Especially when it comes to cutting in the boxes. The word is there are over 500,000 block to be laid on this job. As 480 mentioned, planning and prefab is key or they'll run over you.


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## tates1882 (Sep 3, 2010)

An good electrician/mason tender can run 10 masons. As other said planning and prefab is key, we used masonry boxes and 6" pieces of pipe with tie wire to hold them in place


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## MTW (Aug 28, 2013)

In Florida, I noticed the just notch out where the box is going and snake the romex down through the block.


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## pete87 (Oct 22, 2012)

MTW said:


> In Florida, I noticed the just notch out where the box is going and snake the romex down through the block.[/QUOTE
> 
> 
> 
> ...


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## John Valdes (May 17, 2007)

btharmy said:


> The material and labor savings of PVC over EMT is too much to ignore. Never mind the ease of installation.


I just prefer to deal with one product like EMT. Its faster to. All the same. Same pipe same fittings and same boxes.
But I have done jobs where PVC was required below grade regardless of slab or not.



ampman said:


> EMT in the slab?


Its been done for years and is still done on multi story buildings. Money is saved when EMT/PVC is run in slabs.
Less material and for sure less labor. IMO.
Just be certain to tie your pipe to the rebar after they are done. This suspends the pipe in the slab and keeps it away from the earth/dirt/ground.
If the conduit must be buried under the slab, then no way I would use EMT even though its compliant.



macmikeman said:


> Its his age. We came along before pvc was generally accepted in Florida.
> I haven't run emt in a slab in a long long time, but I have encountered many collapsed rusted emt runs in slabs over the years. Pvc in slabs and dirt for me, emt for the next two or three floors. It is easier to bend it plumb so the boxes sit flush both top and bottom of the switch rings to the face of the block.


Your right about the age thing Mike and we did run PVC for most first floor below grade applications. I can remember when it was all EMT. NM was not even allowed until late 70's early 80's.
But If I was going to do this job, it would all be EMT. One method for the complete job.
If anything need to be below grade or in the dirt, I would use PVC for that.


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## 220/221 (Sep 25, 2007)

sburton224 said:


> I'm sick of chasing masons. PVC underground to ridged 90, changeover to EMT at grade in the block.


That seems silly. Why not stick with PVC all the way? 





> Originally Posted by macmikeman
> Its his age. We came along before pvc was generally accepted in Florida.


Damn, you must be really really old. :laughing: PVC has been in use (here) since (and before) my first construction job in 1970.


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## 3xdad (Jan 25, 2011)

i'm going with masonry boxes and 3/4" pvc stubs up thru the top. On standard 8/8/16 block, what depth tile rings? 

Thanks.


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## Joefixit2 (Nov 16, 2007)

3xdad said:


> i'm going with masonry boxes and 3/4" pvc stubs up thru the top. On standard 8/8/16 block, what depth tile rings?
> 
> Thanks.


 
You don't use rings on masonry boxes. Use deep masons and come out of the top back hole, set your box sticking out however far you need for the final wall finish. On your lights use 4/0's with extensions on them to get back into the cell enough to attach the PVC to a top KO.

What part of NM are you in? I've been all over that state the last few years chasing down my roots.


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## Bootss (Dec 30, 2011)

I guess once you get your message squared away you can get a price for the customer?


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## Knightryder12 (Apr 4, 2013)

3xdad said:


> i'll find out today what the roof framing will be, but how do you guys terminate your pipe when it exits out top course.
> 
> In a comm. bldg. i can see landing in a j-box anywhere up above, but in a house, i'm not so sure.


Couldn't you just stub the conduit straight into the attic space and run NM cable in the attic and use the emt in the walls as a sleeve?


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## telsa (May 22, 2015)

What about Raco's new masonry boxes ?

https://www.hubbell-rtb.com/new_pdf/RA-410 no crops.pdf

Typical example:

695B 
3-1/2" Deep Single-Gang, Welded 
22.5 in ^3 wire room


They avoid the need to fiddle with duct tape, tie wire and positioning rigs.


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## Heavyritefoot (Sep 11, 2015)

Wireless said:


> What about the blue flex? I did one job with it and way easier then PVC!


The blue flex is core line, that's what we call it up here or Ent by code name, it's made by Ipex and royal. I've used hundreds of miles of it in core buildings. Use it in block walls and even underground now. Fast to work with and easier to pull wire thru then emt. Worked with this stuff for the last 15 years in concrete buildings. When you see emt you know someone screwed up. We run distribution, fire alarm, data and security thru it with no issues.


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## IEC (Sep 20, 2015)

Wireless said:


> What about the blue flex? I did one job with it and way easier then PVC!


Smurf pipe (Ent) isn't an effective solution for block walls.

It crushes rather easily, so running it in the slab means that there is a good chance it will be crushed by all the slab guys walking on it and running any wheelbarrows over it. Turning 90's from the slab into the walls leaves a really good opportunity for pinching.

It is allergic to sunlight and will become extremely brittle after a few months in the sun - that's only a problem if the slab meets a hiccup and doesn't get poured until months after it was supposed to, but that does happen and it is something to consider.

It also has several drawbacks in the walls:

You don't want to run horizontally unless absolutely necessary, so you're going to be extending vertically 30" at a time. By the time you get to your top plate, the flexible nature of the tubing means a lot of "S" curves as it leans against the left side of the cell and then falls against the right side of the cell due to its own weight, making fishing and pulling unnecessarily difficult. If it's a poured cell, this will happen every single time and there is a good chance the weight of the mortar will snap the connector on deep block. 

I personally only use Smurf pipe for low-volt (t-stat, etc) in dropped ceiling builds. It doesn't take me that much longer to install EMT and with it I know I have a straight, smooth, attractive pipe run that will last the life f the building.


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## OSSElectric (Sep 28, 2015)

To each his own. Only thing I've got to say is make sure your 90's on your stubs are metal tubing. PVC is too easy to burn a groove into while pulling


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## Cow (Jan 16, 2008)

So far I've only done one block job with grouted cells for a school gymnasium but this is what worked for me. I tried the deep masonry box route first but didn't like it due to the fact you can only get one pipe in the bottom and one out the top. Somebody gave me the idea, Infinity?, to use a deep 4 square box with an 1.5" mud ring instead. This worked much better in my opinion as you could get at least two conduits in the bottom or top with no problem plus you had a lot more wiring room in the box. We used short pieces of conduit tie wired through the 6-32 device holes in the mud ring to pull the box out flush to the block. 

If you go this route install your grounding pigtail first and duct tape the box up to keep the mortar out. We used 3/4" pvc with rigid 90's/FA's in the block. Get all your boxes prepped ahead of time with ma's and everything installed. Ask the mason how tall to make your conduits. They aren't going to want to slide blocks up and over the top of a 10' stick of conduit. On that school job they wanted sticks of conduit no higher than around 40".

I can't stress it enough, make sure you have EVERYTHING you possibly can prepped and staged ahead of time. Masons don't like waiting for electricians to go find the pvc glue or cut some more conduit stubs while they have to wait to lay some block.


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## 220/221 (Sep 25, 2007)

OSSElectric said:


> PVC is too easy to burn a groove into while pulling



PVC is also too easy to avoid burning through. 

The only thing that will burn through it is pull string. A little common sense and a bit of lube will take care of that. 

PVC is SO much easier to work with. Messing around with transitions to metal pipe is unnecessary.



> What about Raco's new masonry boxes ?


It's about time someone made a cut in box for masonry but, aren't those side tabs too wide to be covered by a plate? And, they are too small.

Masonry boxes are roomy and the masons can secure them nicely.


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## Awg-Dawg (Jan 23, 2007)

4" square with tile rings.

They can be wedged to the block, that way the Mason's don't have to try and get the masonry boxes even with the face of the block.

Not that can't, it's just easier with the tile rings.


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## Bogart (Jul 20, 2015)

Is the Block going to be filled? For if not then I would go the method I have used over the years....A Hammer, A chisel, A weighted piece of jack chain MC/BX, a OWB and Madison bars.

If it is going to be filled then I would go the Buy the Mason beer route


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## telsa (May 22, 2015)

220/221 said:


> PVC is also too easy to avoid burning through.
> 
> The only thing that will burn through it is pull string. A little common sense and a bit of lube will take care of that.
> 
> ...


They ARE masonry boxes -- not cut-ins. 

They have one device that is gangable -- but it's NOT a cut-in box.

All have to be installed during the rough-in. :thumbsup:

I rather trust Raco to have gotten their wing dimensions correct. :thumbup:


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## Heavyritefoot (Sep 11, 2015)

Emt is the way to go or core line, don't want to mess around with fa's and emt. Not cheap and a pain to fish thru. Cheaper to do just emt and easier, cut them at 30 inches and your golden. Did alot of schools when I was an apprentice, schools were all done in block. Just make sure the brickys finish the box good and straight and pull the box out half an inch for drywall or your liking. Done some work back in the day where the brickys would want to throw me off there scaffolding. We would mount 4×4 for an automatic door opener and have pipes going up for the power feed, security and fire alarm and back down to the pull stations,electric strikes, card access and door openers. It looked like a octapus.


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## telsa (May 22, 2015)

One tip for all such boxes -- ANY type -- use wax -- say that used by plumbers to seat commodes. 

Press it into the trim screw holes to exclude grout// motar// what not.

A single plumber's ring has enough wax for an entire job.

Otherwise, you're left manually re-tapping the 6-32 threads -- which is brutal on your triple tap -- usually causing it to fail -- while still jambed in the hole. Perfect. :no:

%%%

Preps should be not only made in advance, you should have spares - a few - in case a prep 'wanders off' // gets misplaced on the magic day.

%%%

Never ever use twine or fish steel to pull in your conductors into PVC. 

Use salvaged #10 THHN stranded wire. It's slicker than snot. 

You can re-use it endlessly. It's super low in friction -- the difference is amazing. 

It will never burn through PVC.

When it's worn out -- scrap it anyway -- making this a ZERO COST TOOL.

And it's no challenge to 'edit' the pull wire -- with splices and removals. E-tape and a loop is usually plenty strong. :thumbsup:

And, at the end of your job, your fish steel looks brand new -- with no kinks at all. Just be sure to dry it off lest it rust. :thumbsup:


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## telsa (May 22, 2015)

The Raco winged masonry boxes look to be much more cost effective than duct taped 4sq.

The typical need is for an exterior receptacle in a commercial block wall structure, a perfect match.

They will not mate well with 'broken face' CBU. 

( Where the cinder block is made to look like natural stone.)

For such builds go with extra deep mud rings and the classic 4sq with duct tape.

Such boxes ALSO need CUSTOM Grounding pigtails.... extra longs... STRANDED.

This level of effort will pay off huge during trim-out. You want all of your conductors so long that you can trim-out in 'free air' and then EASILY tuck the assembly back into its box.


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## 220/221 (Sep 25, 2007)

telsa said:


> They ARE masonry boxes -- not cut-ins.


I see, now that I looked closer.



> I rather trust Raco to have gotten their wing dimensions correct. :thumbup:


I don't trust any manufacturer :laughing: Those wings look huge.


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## Joefixit2 (Nov 16, 2007)

220/221 said:


> I don't trust any manufacturer :laughing: Those wings look huge.


 If you read the product features you will see that the front tabs get broken away after the box is set, presumably in concrete or mortar.


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## Bogart (Jul 20, 2015)

telsa said:


> One tip for all such boxes -- ANY type -- use wax -- say that used by plumbers to seat commodes.
> 
> Press it into the trim screw holes to exclude grout// motar// what not.


Excellent Idea


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## walkerj (May 13, 2007)

We are starting a block job


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## 3xdad (Jan 25, 2011)

Post more pics if you get a chance. Thx.


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## IEC (Sep 20, 2015)

walkerj said:


> We are starting a block job


I use those same HD parts boxes. Love them.


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## joe cool (Jun 4, 2009)

I believe the wings are broken off after the mortar sets.



220/221 said:


> I see, now that I looked closer.
> 
> 
> 
> I don't trust any manufacturer :laughing: Those wings look huge.


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## 220/221 (Sep 25, 2007)

Joefixit2 said:


> If you read ...... ....


You lost me there :jester:

I just look at picshures.




> We are starting a block job


That's the way you do it. :thumbsup: 

I assume the ground pigtails are installed?





> One tip for all such boxes -- ANY type -- use wax -- say that used by plumbers to seat commodes.


Duct tape protects the screw holes as well as the inside of the box and conduit. 

I can't imagine ever having to tap mortar out of a screw hole. It doesn't seem like mortar would bond well enough in a tiny 6-32 hole to do any real damage.


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## Joefixit2 (Nov 16, 2007)

220/221 said:


> I can't imagine ever having to tap mortar out of a screw hole. It doesn't seem like mortar would bond well enough in a tiny 6-32 hole to do any real damage.


 My thought too. It doesn't stick at all. I just punch it out with my square drive. Now drywall mud....that's another story


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## walkerj (May 13, 2007)

IEC said:


> I use those same HD parts boxes. Love them.


Those are planters from trees we've been using about 5 years specifically for this



220/221 said:


> I assume the ground pigtails are installed?.


what's this look like? Amateur hour?


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## IEC (Sep 20, 2015)

walkerj said:


> Those are planters from trees we've been using about 5 years specifically for this


LOL. Not those. The two-story stackable Home Depot parts box in front of them with the clear lid.


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## 220/221 (Sep 25, 2007)

walkerj said:


> what's this look like? Amateur hour?


Every single day in this place :jester: :laughing: :jester:

And....The planters are too short/shallow to properly contain the boxes/stubs. 

Are you a real electrician :laughing:


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## 3xdad (Jan 25, 2011)

220/221 said:


> Every single day in this place :jester: :laughing: :jester:


i resemble that.:laughing:


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## walkerj (May 13, 2007)

220/221 said:


> Every single day in this place :jester: :laughing: :jester: And....The planters are too short/shallow to properly contain the boxes/stubs. Are you a real electrician :laughing:


Don't start with me


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## 220/221 (Sep 25, 2007)

Admit it. 

You have the buckets because you're a landscaper :laughing:

You are TREE BARON :laughing:


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## Jlarson (Jun 28, 2009)

Another vote for landscaper here.


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## 3xdad (Jan 25, 2011)

Here's what i'm running into.

i'm using single gang masonry boxes (inspector nixed the use of 4S ).

The block layers are ok with some horizontal runs for room recepts. etc. but i there is almost no room to hit a vertical single gang masonry side to side. We are going to try the boxes horizontal. Any advice?

Secondly, since this is a residence, there are exterior wall lights everywhere. i don't think i can hit them with a conduit out of the switch boxes, so those will just be piped up and out also.

i've always used octagon or round for lighting, but are not readily available in my area as a masonry type box.

The inspector said i can use the single gang masonry for this, but won't that be a fixture mounting bar PITA later on?

Thanks.


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## telsa (May 22, 2015)

3xdad said:


> Here's what i'm running into.
> 
> i'm using single gang masonry boxes (inspector nixed the use of 4S ).
> 
> ...


http://www.garvinindustries.com/ele...BiAn18EHkM-uMGNc5X07ZCgGhJ6OyMMizAaAlo48P8HAQ

You're working with the wrong size box.

You want a masonry box that's 3 1/2" deep.

Wall sconces are rarely heavy, and trim out quickly.

Pancake 'boxes' are commonly surface mounted after the mortar has set, the standard (steel) variety work fine. These will disappear behind the beauty cover of the fixture -- or not. 

Many plastic boxes are also listed as being suitable in masonry applications. The big hitch is the method of attachment. That's where one gets tripped up.

The extra deep masonry boxes are manufactured with your situation in mind. :thumbsup:


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## 3xdad (Jan 25, 2011)

Yes. i'm using 3.5" deep single and double gang boxes, just that when you install two 3/4" TA's on each side, it looks a little tight in there, so i spaced them with a lock ring on the outside which helps a little.

My main question was what are you guys using for the light boxes exterior?

The 4S with 1 1/4" round mud ring (which i would prefer) is out as of now until i hear back from Crouse Hinds on the listing, and a deep octagon with extension ring just seems bad and expensive, so i used a single gang masonry device box. 

i suppose any light mounting bar should work on these, right?

This is a sconce location next to a large door on the right.


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## walkerj (May 13, 2007)

Some walls are up. Only got screwed over on two Saturday's they weren't supposed to work.


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## walkerj (May 13, 2007)

walkerj said:


> Some walls are up. Only got screwed over on two Saturday's they weren't supposed to work.


We put extension rings on the boxes above ceiling to avoid the dreaded floating boxes. 
It ends up much cleaner this way.


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## walkerj (May 13, 2007)

And the plumbers didn't hit the walls for ****. 
Never trust a plumbers layout but be courteous and let them know they may be off. 
This one chose not to listen and he will be riding a jackhammer for a few days. 
Why would you scale a MEP drawing when the architectural gives real dimensions? Fn glue sniffers.


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## te12co2w (Jun 3, 2007)

Arlington makes a box and holder just for this. I didn't know it until I glanced through the latest copy of EC&M yesterday. I don't remember the #. I left the magazine at home


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## Gnome (Dec 25, 2013)

walkerj said:


> We put extension rings on the boxes above ceiling to avoid the dreaded floating boxes.
> It ends up much cleaner this way.


Having never done any block work this thread has been great. But this last comment just went swoosh over my head. Can you elaborate what a _dreaded floating box_ is and how the extension ring makes it cleaner?


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## gryczewskip (Oct 27, 2015)

Then having a bunch of hooks to deal with later

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## walkerj (May 13, 2007)

Gnome said:


> Having never done any block work this thread has been great. But this last comment just went swoosh over my head. Can you elaborate what a dreaded floating box is and how the extension ring makes it cleaner?


If you just stub out a 90, where do you run the conduit to?
You can find the elevation of the bar joists and stub out there but what if you aren't stubbed out right parallel with the bar joist?
You just float a box on the end of the conduit. Lame


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## gryczewskip (Oct 27, 2015)

No, a brick box above ceiling elevation with an extension box. Then you can do whatever. Or pipes out to bar joists

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## 3xdad (Jan 25, 2011)

Gnome said:


> Having never done any block work this thread has been great. But this last comment just went swoosh over my head. Can you elaborate what a _dreaded floating box_ is and how the extension ring makes it cleaner?


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## gryczewskip (Oct 27, 2015)

Yes these are great 

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## 3xdad (Jan 25, 2011)

3xdad said:


> The 4S with 1 1/4" round mud ring (which i would prefer) is out as of now until i hear back from Crouse Hinds on the listing,


From Eaton::blink:


> Good Morning,
> 
> 
> 
> The TP404’s cannot be used with concrete block walls. Our masonry boxes are specifically designed and approved for this application. You may want to take a look at our TP691.


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## Gnome (Dec 25, 2013)

Ah, Now it makes sense.


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