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Posted By: gfretwell Setting boxes in a block wall - 05/02/08 02:13 AM
What kind of box do you all recommend for setting boxes in a concrete block wall, fishing the raceway down the cores. There will be a stucco/plaster finish. Dry location
Posted By: BigB Re: Setting boxes in a block wall - 05/02/08 02:25 AM
Greg, I always use Mason boxes. They are made in both deep and shallow. A true mason box has a lip across the top and bottom for securing the device. I mount them flush or out a little to allow for the stucco. If the stucco is to have styrofoam insulation behind it, then I fasten a handy box extension to it to make up the 1 to 1.5" difference.

Unfortunately, setting boxes in concrete/block/brick is a common thing where I live, I keep a box of Mason boxes on the truck, along with a box of rapid set mortar, and a box of 20 min drywall compound.
Posted By: gfretwell Re: Setting boxes in a block wall - 05/02/08 02:37 AM
Thanks, I was hoping somebody had come up with a new idea that didn't involve mud.
Posted By: homer Re: Setting boxes in a block wall - 05/02/08 11:58 AM
Greg,
The corregated plastic flex is a little easier to fish if you need a raceway, rather than metal flex. It also does not corrode like aluminum can in high moisture environments.
Posted By: gfretwell Re: Setting boxes in a block wall - 05/02/08 01:04 PM
I am using ENT, I assume that is what you are talking about, since it will be cast in concrete at the top of the wall.
We need tie beams here.
I guess masonry boxes it is. I was just amazed that someone had not come up with a surface flange box deep enough to get the KO behind the block web. I sure couldn't find anything in the catalogs
Posted By: gfretwell Re: Setting boxes in a block wall - 05/02/08 02:46 PM
Just a thought, could you "foam" the boxes in?
Posted By: EV607797 Re: Setting boxes in a block wall - 05/02/08 02:49 PM
Greg:

I'm surprised that Arlington Industries hasn't come out with a solution for this yet. This is about the closest thing that I can think of that would address your type of installation, but it's a round box: http://www.aifittings.com/whnew102.htm
Posted By: gfretwell Re: Setting boxes in a block wall - 05/02/08 05:34 PM
OK I am just going with the regular mason boxes and I will just pour these cells when they do the tie beam and dowelled cells. I am going to cut some plywood squares to hold the boxes straight while they get poured in.
Posted By: JValdes Re: Setting boxes in a block wall - 05/03/08 04:04 PM
Can you be there when the block masons are doing the wall. If so you can set the boxes where you want and let them cut them in as they go. You can even run your conduit along with them if they agree. If you don't have to many walls to cover this has always worked good for me.
I use regular 1900 boxes with masking tape.
Posted By: gfretwell Re: Setting boxes in a block wall - 05/03/08 07:45 PM
We are doing a delicate dance with the masons to get this done as easy as possible for them because they are doing me a favor. I would rather work when they are not here so I don't interrupt the flow of their work. I made up some plywood fixtures to hold the boxes with witness lines across the device mounting holes so I can chalk a vertical on the wall and get everything to be straight and level. I will saw cut holes, stuff the pre-piped boxes down the cores and attach them to the plywood via the device holes then tapcon the whole wood to the wall over the hole. When they pour the cells I should have boxes concreted in and sticking out 3/8" for the stucco. It took a while to make my plywood fixtures but it was more fun that watching 3 guys chip out 4 yards of concrete (the current step).
Posted By: Tesla Re: Setting boxes in a block wall - 05/05/08 12:05 AM
Masonry boxes with extensions is my way to get the KO's back into the cinder block cavities. Plenty of duct tape is used. I also install an extra long pigtail at the rough-in.

Recommend ENT/SMURF TUBE with conductors ALREADY installed whenever practical. Combinational raceways with PVC sch 40 below grade and ENT up into the cinder cavities is practical, too.

If you can't install the conductors, install pull lines.

Don't hesitate to bump up the raceway one size for longer runs. 3/4" is a minimum inside a building, 1" is the practical minimum for any pipe that leaves the building.
Posted By: gfretwell Re: Setting boxes in a block wall - 05/05/08 12:29 AM
These are all pretty short and straight runs so stuffing the wire in will be easy. I am going with 3/4". I already installed the ground pigtail, I know better. You will never get a ground screw in there after the cell is poured wink
I am surprised they don't come that way.
We are talking about 5 columns with a couple boxes in each in a 350 sq/ft room.
I am going to home run them all onto a big Carlon box so my wife can change her mind about things. I know she will, I've seen her do it wink
Posted By: u2slow Re: Setting boxes in a block wall - 05/05/08 06:04 AM
I worked on a prison for about 13 months setting boxes with the masonry crew.

I had best luck using 4x4 boxes and deep (1" or 1-1/4") mudrings. You can tie the boxes forward with wire across a scrap of ENT.

Also, you can avoid the connectors at the boxes on poured walls. Leave the ENT long and chop it short after the pour is dry. That way your boxes are adjustable - and quickly installed - as the blocks are being laid.

Posted By: wiking Re: Setting boxes in a block wall - 05/13/08 09:04 PM
It's been awhile and working with masons can range from terrible to easy. A case of beer given for after work can sometimes work wonders.
We always would pre make a bunch of 1900 boxes with about 5' of 3/4 pvc coming out of the top. Since they have to lift the block over the pipe, it shouldn't be too long and there should be plenty of couplings and glue on hand. Pigtail the ground and thread some doubled up tie wire through the back of the box holes and bring it out the front of the deep p-ring with plenty of extra.
Then we would duct tape the whole thing, poking the tie wire through the p-ring.
Communication was the key and if you let most of the masons I used to work with know where and when to put the boxes, they had no problem cutting it out and setting them in.
Then we'd take a cut piece of pvc and use the tie wire to snug the box up to flush (on finished block).
We keep a stash of pieces of busted up block to stick behind the box to snug it in, but a lot of time the masons would take care of that and throw some mud in there too.
Many times when they first hit the job they would need power to be hooked up for their saws, so that was a good time to get everything straightened out how it would happen, but I know what you mean about the dance thing.
Posted By: gfretwell Re: Setting boxes in a block wall - 05/16/08 12:52 AM
OK I made some plywood fixtures to hold the boxes in and poured them with the dowelled cells. I think they came out great and the stucco man will hide all my sins. They sure are not going anywhere.
http://esteroriverheights.com/electrical/double_box.jpg
http://esteroriverheights.com/electrical/single_box.jpg
Posted By: XtheEdgeX Re: Setting boxes in a block wall - 05/21/08 08:16 PM
I've "chased masons" a lot in the past, and I've always done it the way wiking described.
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