Argh, need help finding a certain electrical box

[bzinsky]

So I am in deperate need of finding a single gang electrical box that is atleast 12 cubic inches and is no thicker than 3/4 inch.

I have to install about 50 boxes on exterior walls which are comprised of cinder block, then 1by, then sheetrock. We cannot find a box that is shallow enough to be sheetrocked.

We tired a shallow 2 gang box which has a cover plate that turns it into a single gang, but as it sits now the 2 gang box is too thick and we'd need to cut a 2 gang sized hole in the sheetrock to install it. I'm looking into creative options like ultra shallow 3 gang boxes that have a single gang conversion cover, but can't find any.

What the hell do people do when they have to install electrical boxes with 1by framing over cinderblocks.

Also we can not bump out the wall for various reasons too long to explain. Please just try your best to disregard it as an option.

Anybody have any suggestions?

 

[Rock knocker]

A single gang box is about 3 3/4 X 1 1/2 inches. At a depth of 3/4", given Newtonian science, a 12 cubic inch box would not be possible. Using quantum physics you might be able to come up with 12 cubic inches with your other dimensions with the help of Schroders cat.

 

[warren57]

So I am in deperate need of finding a single gang electrical box that is atleast 12 cubic inches and is no thicker than 3/4 inch.

I have to install about 50 boxes on exterior walls which are comprised of cinder block, then 1by, then sheetrock. We cannot find a box that is shallow enough to be sheetrocked.

We tired a shallow 2 gang box which has a cover plate that turns it into a single gang, but as it sits now the 2 gang box is too thick and we'd need to cut a 2 gang sized hole in the sheetrock to install it. I'm looking into creative options like ultra shallow 3 gang boxes that have a single gang conversion cover, but can't find any.

What the hell do people do when they have to install electrical boxes with 1by framing over cinderblocks.

Also we can not bump out the wall for various reasons too long to explain. Please just try your best to disregard it as an option.

Anybody have any suggestions?

When I did mine, I used 2 gang boxes with a flat plate 1 gang adaptor. It only adds the thickness of the plate (which isn't much, they are thin). If you need more room than that, you will need less wires or more boxes. I've seen times people had to use multiple boxes at switch locations. Not very pretty, but the only option I guess.

 

[bzinsky]

When I did mine, I used 2 gang boxes with a flat plate 1 gang adaptor. It only adds the thickness of the plate (which isn't much, they are thin). If you need more room than that, you will need less wires or more boxes. I've seen times people had to use multiple boxes at switch locations. Not very pretty, but the only option I guess.

that's what I have now, but the 2 gang box is just too thick. I was hoping there was a 3 gang version of that somewhere out there.

 

[APEowner]

This may be a good application for some kind of surface mount raceway system.

 

[bzinsky]

A single gang box is about 3 3/4 X 1 1/2 inches. At a depth of 3/4", given Newtonian science, a 12 cubic inch box would not be possible. Using quantum physics you might be able to come up with 12 cubic inches with your other dimensions with the help of Schroders cat.

I just read all of Einsteins and Hawkings work and figured out that the box could be wider in the back and smaller in the front to achieve the desired volume.

 

[Rock knocker]

(3.75x1.5x0.75=4.2)<12=sol

 

[Rock knocker]

I just read all of Einsteins and Hawkings work and figured out that the box could be wider in the back and smaller in the front to achieve the desired volume.

Then that wouldn't be a single gang box. That would be a two gang box with a single gang 1/2 mud ring.

My math stands

 

[MoonRise]

Don't think you can get 12 cu inch or greater in that thin of a box.

A "pancake" box can get you about 6 in3.

http://www.orbitelectric.com/steel-products/electrical-junction-boxes/pancake-boxes.html

A shallow 2-gang 4 inch square new-work box from Pass&Seymour has a capacity of 17 in3 but a listed depth of 1-1/4".

http://www.legrand.us/passandseymou.../4-inch-square-boxes-and-covers/s4418bac.aspx

As to what to do, that is why the framing/furring has to allow enough depth in order to mount the electrical boxes.

And 'sheetrock' on an exterior wall? As in you have the block, and then the 1x furring, and then the 'sheetrock', and then the outdoors?

Or are you trying to 'finish' off a basement type wall and the drywall is on the inside of the building and the concrete blocks are the 'outside' surface?

Solutions might include reframing so that there actually is enough depth behind the drywall to put the electrical boxes (I know you said you really don't want to do that, but sometimes you just have to), surface-mounting the electrical (conduit and 'exposed' boxes, might be too 'industrial' looking for a 'finished' basement), putting a double layer of drywall up, or (uggh) knocking a bunch of holes/recesses in the concrete in order to let the electrical boxes be installed.

Your call.

 

[bzinsky]

This may be a good application for some kind of surface mount raceway system.

Can't, long story, there are some clearance issues if I need anything coming out of the wall further. Also I think it would be a crime to use wire molding during a gut renovation.

 

[bzinsky]

Don't think you can get 12 cu inch or greater in that thin of a box.

A "pancake" box can get you about 6 in3.

http://www.orbitelectric.com/steel-products/electrical-junction-boxes/pancake-boxes.html

A shallow 2-gang 4 inch square new-work box from Pass&Seymour has a capacity of 17 in3 but a listed depth of 1-1/4".

http://www.legrand.us/passandseymou.../4-inch-square-boxes-and-covers/s4418bac.aspx

As to what to do, that is why the framing/furring has to allow enough depth in order to mount the electrical boxes.

And 'sheetrock' on an exterior wall? As in you have the block, and then the 1x furring, and then the 'sheetrock', and then the outdoors?

Or are you trying to 'finish' off a basement type wall and the drywall is on the inside of the building and the concrete blocks are the 'outside' surface?

Solutions might include reframing so that there actually is enough depth behind the drywall to put the electrical boxes (I know you said you really don't want to do that, but sometimes you just have to), surface-mounting the electrical (conduit and 'exposed' boxes, might be too 'industrial' looking for a 'finished' basement), putting a double layer of drywall up, or (uggh) knocking a bunch of holes/recesses in the concrete in order to let the electrical boxes be installed.

Your call.

These are inside finished apartments, yes, block, furing, sheetrock. That's how they the origional framing was. I can't bump it out because I only have 1/4 inch to spare from the fridge door hitting the other side of the counters. If the fridge is mounted any further out I'll need to spend an enormous amount of money on french door fridges, which I can't really do anyways because the fridge is mounted in a corner and the french door needs room on the side to open. Basically looking at $15-20k extra if I bump out the walls. It'd be cheaper to buy a 3d printer, pay engineers to design a box in CAD, and print the boxes out.

 

[Rock knocker]

It'd be cheaper to buy a 3d printer, pay engineers to design a box in CAD, and print the boxes out.

Don't forget the UL certs.


I'd say knock some holes in the CMU

 

[bzinsky]

Then that wouldn't be a single gang box. That would be a two gang box with a single gang 1/2 mud ring.

My math stands

Physics have been defied

I present to you a single gang box that is wider in the back

http://www.homedepot.com/p/Carlon-1-Gang-17-cu-in-Shallow-Old-Work-Box-B117RSWR/202077341

 

[bzinsky]

Don't forget the UL certs.


I'd say knock some holes in the CMU

Ugh, I'd hate knock holes in cinderblock, especially in 3 story buildings with 40+ souls inside.

There's got to be a creative solution somewhere.

Maybe some sort of ultra shallow floor box? I've never installed one to be honest.

 

[Rock knocker]

Is that going to work?

 

[Rock knocker]

What's going in the boxes?

 

[Rock knocker]

I assume you own the building because if you were in the trades, you'd say CMU

 

[Eriehunter]

You are going to end up knocking holes in the CMU, use 1 1/2 hat track or fir out more on your fir job if that is done already.

There is a shallower box than 1 1/2 but I have rarely used them, maybe 3/4 deep IIRC. so the box would be 4x4x3/4 then you would need a 1 gang device ring to match the thickness of the drywall. You would have to attach the box directly to the CMU wall with a concrete anchor. I would get you a steel city part number but I don't have my catalog handy.

 

[bzinsky]

What's going in the boxes?

outlets

Some are gfi's, but where there are GFI's there is tile backslash. Between the tile and sheet rock I should have no problem fitting a gfi inside a 3/4inch box with mudring

 

[bzinsky]

You are going to end up knocking holes in the CMU, use 1 1/2 hat track or fir out more on your fir job if that is done already.

There is a shallower box than 1 1/2 but I have rarely used them, maybe 3/4 deep IIRC. so the box would be 4x4x3/4 then you would need a 1 gang device ring to match the thickness of the drywall. You would have to attach the box directly to the CMU wall with a concrete anchor. I would get you a steel city part number but I don't have my catalog handy.

I just spent like 15 minutes on the steel city catalog online, there's like a 1000 boxes and the worlds worst search engine.

http://www-public.tnb.com/ps/endeca/index.cgi?a=nav&remove=601+307+647

If you can find it that would be awesome, PM me your address and I'll ship you a beer.

I did find the Raco 418, it might work, but specifies for low voltage. Not sure what the difference is.

http://www.lowes.com/pd_102148-427-418_0__?productId=3181543

 

[bzinsky]

Is that going to work?

nope the side piece with the extra volume is too thick by about a 3/8ths of an inch

Some of the walls are not demo'd, so can't really easily bump those walls out a little with lathe.

 

[MN4x4]

I've faced a similar problem, and I'm pretty sure you're gonna end up doing something other than a box.

In order to get a 12 cu in box that is only 3/4 in thick, if you keep it at 4" tall it would have to also be 4" wide. Since most boxes aren't QUITE 4" tall, you'd be looking at a 3-gang 3/4" deep box - which I've never seen, nor could google find. Also, trying to wire devices into a box that shallow is going to be a PITA, even if you end up with the extra 1/2" or 5/8" with plaster ring.

Have you asked your electrical inspector if they are aware of any options? If you've got a good they can be a wealth of information.

 

[Eriehunter]

I'll try and look when I get home.

 

[bzinsky]

I've faced a similar problem, and I'm pretty sure you're gonna end up doing something other than a box.

In order to get a 12 cu in box that is only 3/4 in thick, if you keep it at 4" tall it would have to also be 4" wide. Since most boxes aren't QUITE 4" tall, you'd be looking at a 3-gang 3/4" deep box - which I've never seen, nor could google find. Also, trying to wire devices into a box that shallow is going to be a PITA, even if you end up with the extra 1/2" or 5/8" with plaster ring.

Have you asked your electrical inspector if they are aware of any options? If you've got a good they can be a wealth of information.

electrician and inspector were right there with me while we were trying to find a solution, neither of them knew what to do, only that I need 12 cubic inches in there some how. Wiring shouldn't be too bad, as the total box volume is not really 4x4x3/4. When you put a 1/2inch thick mud ring, it essentially adds 4 cubic inches to the box. Leaving a total just south of 16 cubic inches, plenty of space to wire up a single outlet.

With the outlets that are GFI, because of the tile backsplash, I'll have to use like a 3/4"-1" mudring, or an extender, giving even more volume and depth.

 

[bzinsky]

It seems on a few other forums I found posts about this seemingly common problem with not so common solution, they just chisel out the block.

I have little experience doing that. Anybody think it would have any effect on structural integrity?

 

[zmaxmotorsports]

Use 1 1/2" firring strips(2x2),then you can use a 4sq box with a plaster ring.

 

[rlitman]

I have to install about 50 boxes on exterior walls which are comprised of cinder block, then 1by, then sheetrock.

When you say 1by, you mean there's a 3/4" space?
I cannot see how anybody is going to make an outlet box too thin to hold an outlet. Yes, I've seen boxes shallower than 1 1/2". They're 1 1/4".

The ground pin on a Nema 5-15 is just under 7/8" long. By necessity, an outlet must be deeper than that (by the thickness of the back cover at least), so I really don't see how an outlet can be much thinner than 1".
Even with a 1" deep box, you've got to side wire the outlet (ok), and then have the wires make a sharp turn as they exit the screws (not ok; what if you strip the wire 1/16" too long). There's no room for a wire to even cross behind the outlet.

The thinnest GFI outlets I've seen are the new Levitton ones. They're advertised to be 1.32" deep. That'll stick out even with a mud ring.

It ***** that the sheetrock is up already. If you're going to chisel a hole in the block, you really want to aim for a cavity. If you can cut out a large square of sheetrock and use a diamond blade in an angle grinder, cutting a nice hole in the block would be easy. Then just put the sheetrock back.
That should be simple behind a fridge, or in a place that tile backsplash is going to be added in the future. Not so simple if it is existing.

 

[Eriehunter]

I looked as best I can, I must have been thinking about the 1 1/4 deep 4 square boxes.

 

[Rock knocker]

It seems on a few other forums I found posts about this seemingly common problem with not so common solution, they just chisel out the block.

I have little experience doing that. Anybody think it would have any effect on structural integrity?

It is the common solution, but if you are concerned you should contact a PE

 

[bzinsky]

When you say 1by, you mean there's a 3/4" space?
I cannot see how anybody is going to make an outlet box too thin to hold an outlet. Yes, I've seen boxes shallower than 1 1/2". They're 1 1/4".

The ground pin on a Nema 5-15 is just under 7/8" long. By necessity, an outlet must be deeper than that (by the thickness of the back cover at least), so I really don't see how an outlet can be much thinner than 1".
Even with a 1" deep box, you've got to side wire the outlet (ok), and then have the wires make a sharp turn as they exit the screws (not ok; what if you strip the wire 1/16" too long). There's no room for a wire to even cross behind the outlet.

The thinnest GFI outlets I've seen are the new Levitton ones. They're advertised to be 1.32" deep. That'll stick out even with a mud ring.

It ***** that the sheetrock is up already. If you're going to chisel a hole in the block, you really want to aim for a cavity. If you can cut out a large square of sheetrock and use a diamond blade in an angle grinder, cutting a nice hole in the block would be easy. Then just put the sheetrock back.
That should be simple behind a fridge, or in a place that tile backsplash is going to be added in the future. Not so simple if it is existing.

The 3/4 inch box is just the first layer in a 2 layer box. It's not like it's going to leave 3/4inches of total space for the outlet.

 

[MN4x4]

I just today used one of these (mentioned earlier in this thread)

http://www.homedepot.com/p/Carlon-1...hoxjpl&cm_mmc=CJ-_-6147012-_-11210757&cj=true

and it worked out very well for me. But it still won't work in your situation - sorry!

 

[RivennHewn]

Oversized cover plates?

I know they make them, I just don't know how much bigger they are.

You could cut the drywall around the box and use a flat mounting ring, and maybe(?) the oversized cover plate will work.

 

[mm08822]

Consider a carlon box# B108R-UPC. It is 1.25" deep and then add a wiremold extension ring on top of Sheetrock. Planning your cable routing to preserve box fill limits may be your challenge.

 

[Norcal]

Chipping out the block behind the boxes is the only option I see, but since it's a apartment (condo?) I would recommend consulting a engineer before doing so.

 

[bzinsky]

Chipping out the block behind the boxes is the only option I see, but since it's a apartment (condo?) I would recommend consulting a engineer before doing so.

Here's my experiences with engineers

Honestly, I've hired an engineer several times for something like this, I get underwhelming results every time. For little stuff like this, they are only good for passing on some liability. They don't do complex load calcs for this little stuff, it's more akin to someone with a formal education coming in and saying "yup, looks good to me"

They always send the guys straight out of college for this stuff too.

Waste of money IMO unless I'm looking to pass the blame for the building collapsing.

Infact, I think nearly everytime I hire engineers I am always dissapointed. Most of them are just regular people that went to engineering school, the good ones, the ones that aren't just capable of looking up codes and making CAD drawing, and are actually of use to mechanically inclined people like us (other than obtaining formal prints), are rare and cost a lot of money.

Just the other month, I had to get an engineer draw some prints for a garage repair. 1 story 4 car garage, the garage had 2 way oversized steel Ibeams in it from the 1920's, the front end of the roof was in bad shape from long term leak damage and we needed another ibeam. This freaking engineer spec'd the same Ibeams as it had in it, and these absolutely rediculous high grade steel 5 inch columns, and monstrous footing for the columns. I spend all this time finding the best way to obtain this stuff, since I hardly ever buy steel, and the 4 columns alone were like $2k. I finally call him up, I'm say "man, why did you spec this insane steel, this isn't a 5 story building, it's just 1 story garage.

His response "it's what was there, I can look into cheaper options, my bad"

He makes some new prints, 4" inch columns, regular cheap hot rolled steel, and some little ibeam two guys can lift. It's still over kill, but whatever, I'll take it. The price of the steel for the project went from about $3k to $200.

That sums up my experiences with most engineers. I was under the impression this guy was looking up code books and doing load calcs at his office like you would imagine an engineer would, nope, just wingin it, and doing a terrible job too.

They should seriously make engineering a more difficult field to get into. Instead it's like a generic career now for a lot of people that don't know what else to major in. Hell, my little sister is a Mechanical engineer, very intelligent and very driven, to the point where she could be good at anything just from sheer will power. Most people on this board probably have far more natural mechanical intelligence.

You don't get the good engineers until you develop a strong relationship or spend over $10k on a project, even then they send their college grad underlings for little stuff like looking at potential holes in concrete block.

 

[toplessHO]

While I dont profess to be an expert in residential wiring,having done my fair share of them
in lean times, its common place to knock the block out with a hammer in a cavity right next to the furring strip. If it takes more than a minute extra per hole to make that cavity find a new electrician.Score the block with a good wide masonry chisel and come up with a nice neat hole. Sounding with a hammer will tell if its a poured cell or not. You may want to consider a GFCI breaker at panel or put the GFCI outlet as a feed thru upstream in a location that will readily accept a deeper box.Another option is a 4sqx1.25 box and a flat offset single gang cover,floated in with mud around it to blend in.

 

[Gerald O]

Do the outlet covers need to be flush with the sheetrock or can they protrude?

If they don't have to be flush then how about using a deeper box and trimming around the protruding part with a nice molding. The cover can then be flush to the molding.

 

[Rock knocker]

We are starting to go around in circles while you are looking for a degree of affirmation you won't receive here.

Most here would knock out the CMU and get on with life. Either do it or don't do it.

Knocking out the CMU is the common way to deal with this situation, and although I can't see your particular application, clearance holes in the block almost never affects the structural strength or fire assembly. If you are further concerned consult an engineer, or not.

It will be difficult to find boxes 3/4" deep which will give you the volume you need. The Carlon boxes referenced above may work, but they are old work boxes. Use them if they will work. Or don't use them, it's up to you.

 

[Rock knocker]

Here's my experiences with engineers

Honestly, I've hired an engineer several times for something like this, I get underwhelming results every time. For little stuff like this, they are only good for passing on some liability. They don't do complex load calcs for this little stuff, it's more akin to someone with a formal education coming in and saying "yup, looks good to me"

They always send the guys straight out of college for this stuff too.

Waste of money IMO unless I'm looking to pass the blame for the building collapsing.

Infact, I think nearly everytime I hire engineers I am always dissapointed. Most of them are just regular people that went to engineering school, the good ones, the ones that aren't just capable of looking up codes and making CAD drawing, and are actually of use to mechanically inclined people like us (other than obtaining formal prints), are rare and cost a lot of money.

Just the other month, I had to get an engineer draw some prints for a garage repair. 1 story 4 car garage, the garage had 2 way oversized steel Ibeams in it from the 1920's, the front end of the roof was in bad shape from long term leak damage and we needed another ibeam. This freaking engineer spec'd the same Ibeams as it had in it, and these absolutely rediculous high grade steel 5 inch columns, and monstrous footing for the columns. I spend all this time finding the best way to obtain this stuff, since I hardly ever buy steel, and the 4 columns alone were like $2k. I finally call him up, I'm say "man, why did you spec this insane steel, this isn't a 5 story building, it's just 1 story garage.

His response "it's what was there, I can look into cheaper options, my bad"

He makes some new prints, 4" inch columns, regular cheap hot rolled steel, and some little ibeam two guys can lift. It's still over kill, but whatever, I'll take it. The price of the steel for the project went from about $3k to $200.

That sums up my experiences with most engineers. I was under the impression this guy was looking up code books and doing load calcs at his office like you would imagine an engineer would, nope, just wingin it, and doing a terrible job too.

They should seriously make engineering a more difficult field to get into. Instead it's like a generic career now for a lot of people that don't know what else to major in. Hell, my little sister is a Mechanical engineer, very intelligent and very driven, to the point where she could be good at anything just from sheer will power. Most people on this board probably have far more natural mechanical intelligence.

You don't get the good engineers until you develop a strong relationship or spend over $10k on a project, even then they send their college grad underlings for little stuff like looking at potential holes in concrete block.

I've worked with engineers almost my entire working career and your view is simplistic, rather insulting and mostly wrong.

 

[Rickss96]

I've worked with engineers almost my entire working career and your view is simplistic, rather insulting and mostly wrong.

+1 on Rock knocker's reply. As you may have discovered, the best time to consult engineering is in the planning stages so that you do not end up with boxes that won't fit. And based on your comment you do understand how the 'good engineers' work:

You don't get the good engineers until you develop a strong relationship or spend over $10k on a project, even then they send their college grad underlings ...

The competent engineers don't want to waste their time on your trivial retrofit problems. As others have said before "You get what you pay for."