# 90 out at top of wall?



## cwebb (Jun 26, 2013)

When I chase masons I usually turn out a 90 after the wall is above the drop ceiling or put a 4sq box with two extension boxes so i can run pipe on the wall if there is not precast or building steel to run pipe on. I know that you are not supposed to run pipe out of an extension box because it is supposed to be removable. Has anyone used a wall bracket that would mount above a emt 90 for a box support so i could run the 90 into the box then offset the conduit back to the wall to the left and right. I don't like using shepards hooks I would rather use LBs and an offset. If you have any good ideas let me know. I looked in the caddy book and only found expensive brackets that hold thousands of lbs. Thinking about making my own out of steel stud scraps.


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## cwebb (Jun 26, 2013)

I don't think cutting the 90s down, putting a BOB on them, and putting a 4sq on top is a good idea because the metal 90 wouldn't be grounded the pipe turns to pvc in the block wall.


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## joebanana (Dec 21, 2010)

cwebb said:


> When I chase masons I usually turn out a 90 after the wall is above the drop ceiling or put a 4sq box with two extension boxes so i can run pipe on the wall if there is not precast or building steel to run pipe on. I know that you are not supposed to run pipe out of an extension box because it is supposed to be removable. Has anyone used a wall bracket that would mount above a emt 90 for a box support so i could run the 90 into the box then offset the conduit back to the wall to the left and right. I don't like using shepards hooks I would rather use LBs and an offset. If you have any good ideas let me know. I looked in the caddy book and only found expensive brackets that hold thousands of lbs. Thinking about making my own out of steel stud scraps.


Can you drop some 3/8" all-thread from above with a beam clamp, or a lag-stud, and hang the box from that? Hang the pipe with mini's.
Not sure I'm seein the whole picture. Just stabbing at it.


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## cwebb (Jun 26, 2013)

the trusses that hold the ceiling are 20ft or more above the block walls so there is nothing to run on except the walls and there are 90s above every box. no underground got put in


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## RunningSparky (Feb 9, 2013)

One foot lengths of thin strut, L-bracketed off the wall, to top of box, nut/bolt to box?


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## telsa (May 22, 2015)

cwebb said:


> When I chase masons I usually turn out a 90 after the wall is above the drop ceiling or put a 4sq box with two extension boxes so i can run pipe on the wall if there is not precast or building steel to run pipe on. I know that you are not supposed to run pipe out of an extension box because it is supposed to be removable. Has anyone used a wall bracket that would mount above a emt 90 for a box support so i could run the 90 into the box then offset the conduit back to the wall to the left and right. I don't like using shepards hooks I would rather use LBs and an offset. If you have any good ideas let me know. I looked in the caddy book and only found expensive brackets that hold thousands of lbs. Thinking about making my own out of steel stud scraps.


Use a tight radius (trick) bending shoe: Benfield #8 -- and EMT -- to turn out from the CBU cavity.

This one-shot bender// shoe is shown on page 87 of the Benfield Conduit Bending Manual. 

( figure 44 )

What makes this combination shoe so trick ?

The ultimate minimum NEC bending radius for 3/4" and 1/2" EMT.

Yes, it's TIGHTER than ANY other one-shot shoe on the market.

You will have to custom order it from your distributor as it is not stocked locally.

Most fellas have never seen this puppy.

The extreme tight radius lets you run EMT in very tight quarters -- such as CBU.

If you don't have a copy of the BCBM... get one.

ISBN 10-0-87288-510-0
_
Problem solved._


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## splatz (May 23, 2015)

I can only translate about 50% of the OP's posts but I know what he's talking about. A lot of the industrial parks around here have a big warehouse or manufacturing plant built in steel engineered buildings, these things go up so fast it's incredible. 

Some places they add the offices to the outside of the big structure, so the office has a low roof like a normal building. Others they put the office space inside the big structure along the outside wall, so you lift a ceiling tile in the office and there's nothing up to the bottom of the trusses 28' above. 

So if you're coming out of a block wall in there, you'll want to support the conduit somewhere at the top of the wall. 

I do not follow the idea with using a box stacked with two extensions. 

I don't mind a shepherd's crook, which is really nothing more than an offset below the 90 so the back of the 90 is at the back of the block. This makes the conduit more or less level / straight at the front of the block so you can get a clamp on it. 

Depending how much of a mess the mortar is, you might be able to get a minerallac clamp on INSIDE the top block cell. You would just drill a hole through the face of the block wall into the center of the cell, and attach it with a bolt, a nut, and a washer. 

A short piece of tall strut and an angle bracket would work but it would be expensive, you're basically making an L bracket out of strut. The strut fittings are overbuilt for this, not cheap. 

You could just bend a 90 with a short stub from a scrap, and attach that to the face of the wall with two one hole straps, and use back to back minerallacs to attach the scrap to the conduit. You're basically taking a piece of scrap and bending a 90 in it to make a shelf bracket. If you can get them and don't mind spending a few bucks you could use these instead of the back to back minerallacs:


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## cabletie (Feb 12, 2011)

Since the box has to be supported when attached to the stub out, I have two go to methods. 

Use a 1 gang masonary box or 4"sq w/1 gang 1-1/2" raise mud ring on the box in the wall. Later add a Raco #187 box on that. A #187 box will also extend a two gang masonary box or two gang mud ring if you want more room reaching into the box. 

If you want more options later like running the conduit right off the stub, then stub the conduit out. Later if you use a box, just support it with a Caddy TSGB16. The same bracket you would use in a stud wall. Instead of bending the bracket to recess the box in the wall, bend it opposite, to hold the box off the wall. You have to cut the stub back a little or notch the TSGB16 to make it stand off the wall farther. I'll see if I can snap a picture later.


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## Southeast Power (Jan 18, 2009)

cwebb said:


> When I chase masons I usually turn out a 90 after the wall is above the drop ceiling or put a 4sq box with two extension boxes so i can run pipe on the wall if there is not precast or building steel to run pipe on. I know that you are not supposed to run pipe out of an extension box because it is supposed to be removable. Has anyone used a wall bracket that would mount above a emt 90 for a box support so i could run the 90 into the box then offset the conduit back to the wall to the left and right. I don't like using shepards hooks I would rather use LBs and an offset. If you have any good ideas let me know. I looked in the caddy book and only found expensive brackets that hold thousands of lbs. Thinking about making my own out of steel stud scraps.


I don't see the problem with using extension rings and then piping out of them.
I would under no circumstance use a short radius bender suggested here.
If you were determined to come out of the wall and then hit a box or continue piping without a box, put a 4" kick on the vertical side in the block cell and lay it flat on the wall horizontally.
From there you could either install a surface mounted box or a coupling and keep going.
If it's a hard ceiling, you can stub up two conduits and left and right to other boxes in the wall.


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## glen1971 (Oct 10, 2012)

Offest out of the block wall... Then you can mount a 4x4 to it, or a coupling and run it in whatever direction you need to.. Just tape over the end first. If you measure properly, you can bring the offset out at the top or bottom of the course and make your masons happier..


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## cwebb (Jun 26, 2013)

Thank you for the advice, I like the idea of offsetting out of the wall and kicking a 90 out of the wall. I have used both of these methods in the past. On drywalled walls the carpenters complained about where offsets landed on there board. I took this job over from another electrician and there are already 90s sticking out of the block with out anywhere except the wall to run conduit. I think caddy or one of the other manufactures should make a 8X8 inch triangle bracket like a shelf bracket for box and conduit support. Strut 90s and strut is to expensive when wiring a large project.


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## Roger (Jul 7, 2007)

cwebb said:


> I know that you are not supposed to run pipe out of an extension box because it is supposed to be removable.


Where did you get that idea?

Roger


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## cwebb (Jun 26, 2013)

Hi Rodger I think an inspector or another electrician told me that it is a violation, but the only violation I can find is if there was an existing installation and you added the extension box. If the wires are not long enough than it would violate 300.14. I like this method of coming out of a wall just need to make longer ground tails. The masons prefer 90s but a case of beer keeps the peace.


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## Roger (Jul 7, 2007)

cwebb said:


> Hi Rodger I think an inspector or another electrician told me that it is a violation, but the only violation I can find is if there was an existing installation and you added the extension box. If the wires are not long enough than it would violate 300.14. I like this method of coming out of a wall just need to make longer ground tails. The masons prefer 90s but a case of beer keeps the peace.


I agree that the conductor length could be a problem but using an extension ring to bring a box beyond the surface and running conduit from the extension ring is legal and makes for a good installation. Where people get confused is when they read the exception 314.22 which is talking about a blank cover with a KO to run flexible wiring methods for extending the wiring.



Roger


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## B-Nabs (Jun 4, 2014)

You could get some steel stud track, cut a piece a couple feet long, snip it and bend it into an L, and screw another little piece on diagonally to hold it in that shape. Fasten one leg of the L to the wall, then fasten your box to the other leg. Like the strut idea but cheaper. 

Sent from my SM-G920W8 using Tapatalk


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## bostonPedro (Nov 14, 2017)

cabletie said:


> Since the box has to be supported when attached to the stub out, I have two go to methods.
> 
> Use a 1 gang masonary box or 4"sq w/1 gang 1-1/2" raise mud ring on the box in the wall. Later add a Raco #187 box on that. A #187 box will also extend a two gang masonary box or two gang mud ring if you want more room reaching into the box.
> 
> Use the same boxes. They make piping so much easier than trying to pipe and connect stub 90's


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## sburton224 (Feb 28, 2013)

In my experience the stub 90s coming out of the wall normally have some give in them where you can cut them short, put a connector on the end and attach it the back of a 4 square. Then push it back in the wall and Tapcon the box to the block...run your conduit from the box on to the next or wherever it goes. I've used this method numerous times when there aren't purlings to hit. If the stub is coming out of a cell that has been filled with grout this obviously wont work.


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## cwebb (Jun 26, 2013)

I emailed caddy and they suggested using a FSB12. I ordered a box and used a couple They seem to support the box securely with two tapcons back to the block wall. I also used a TSBG16 like cable tie suggested, just wish there was a listed box support for this application. In the future I think a masonry box with the 187 is the way to go.


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## cabletie (Feb 12, 2011)

We did a five story prison expansion job ten years ago. There was some CMU walls but most was precast concrete. All vertical conduit had to be concealed in the walls, all ceiling conduit was exposed.

Every precast panel had to be coordinated with the precast company for the required boxes for power, light, data, security and door locks. Very time consuming. If stub outs were used they had to finish flush. Most of the time they didn't leave it flush with a coupling or a void around the stub. Made coming off with conduit or box a pain. Luckily most stub outs were boxes with the #187 extension boxes.


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## Cow (Jan 16, 2008)

cabletie said:


> Since the box has to be supported when attached to the stub out, I have two go to methods.
> 
> Use a 1 gang masonary box or* 4"sq w/1 gang 1-1/2" raise mud ring on the box in the wall. Later add a Raco #187 box on that.* A #187 box will also extend a two gang masonary box or two gang mud ring if you want more room reaching into the box.


We used this method in a school gym, it works well.


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