Old work ceilng boxes no go?

[ritelec]

I have a few holes cut for the slater old work plastic round boxes.
They are listed for 20lbs. (see luminaries support must be rated for 50lb)
Started reading about to see if they where listed for ceiling..... couldn't find any thing.
A link brought me to an older (2010) post here........ (which is closed).......I see through that post and article 314.27 (A) the requirements...........

Are there any exceptions for ceiling use (50 or 20 lb rated boxes) for something that's lighter than a feather like a smoke detector..
Also the post mentions how the box is supported from the sheet rock so it's a no go (for luminaries) What if your ceiling was constructed of plywood........or in my current case, wood lathe/plaster???


Thank you

I must mention too,the cats meow..............finding a beam to install a pancake box.......alls beautiful, then I see the pancakes I was going to use (raco 4x1/2) have a cu " of 6.0...........there goes a 3 wire smoke (unless you guys can find
me an exception like the ground in a 3 wire nm doesn't count in conductor fill of a box when installing pancake boxes for smoke detectors)
Same thing for the raco "fan"cake box for a fan/light.........6.5 cu"...................dooped !!

 

[George Stolz]

You can use round cut-ins for a smoke detector. Smokes are not luminaires.

With a little investigation you'll probably find the box was listed to carry that weight when installed in plywood, not drywall. Therefore, there's little extra credit to be had for installing in a lathe and plaster ceiling.

Pancake boxes of differing designs are difficult to use when dealing with box fill.

 

[ritelec]

You can use round cut-ins for a smoke detector. Smokes are not luminaires.

With a little investigation you'll probably find the box was listed to carry that weight when installed in plywood, not drywall. Therefore, there's little extra credit to be had for installing in a lathe and plaster ceiling.

Pancake boxes of differing designs are difficult to use when dealing with box fill.

Thank you George Stolz....I'm doing a happy dance on the smokes right now.....

The pancake... I think I may get thru that..
They still make bx right (ac)............2nd floor bed, splice nm to bx (attic).... bx to the pancake (fancake) 6 cu in. and grounded.

Thanks again.
Rich

 

[George Stolz]

Sounds like extra work, knock yourself out.

 

[mjf]

FYI, Kidde is now manufacturing wireless, interconnected smoke detectors. You can even tie them into an existing hardwired interconnected system.

material cost is greater.
labor is greatly reduced.

old work or pancake have no fill issues.

 

[infinity]

Thank you George Stolz....I'm doing a happy dance on the smokes right now.....

The pancake... I think I may get thru that..
They still make bx right (ac)............2nd floor bed, splice nm to bx (attic).... bx to the pancake (fancake) 6 cu in. and grounded.

Thanks again.
Rich

We have always used AC cable with 1/2" pancake boxes to meet the fill requirement. Simple installation, 4" hole saw, find the beam and drill away. You can use 14/3 or 12/2 depending on the number of conductors you need.

 

[ritelec]

We have always used AC cable with 1/2" pancake boxes to meet the fill requirement. Simple installation, 4" hole saw, find the beam and drill away. You can use 14/3 or 12/2 depending on the number of conductors you need.

Thank you infinity.........

 

[ritelec]

Sounds like extra work, knock yourself out.

yes it is. I agree.
The jobs being done in nm....... what would you suggest? I know they make the plastic pancake type box that goes up higher to the side of the beam
to give the extra area.......but, it's old work, lathe plaster....and a few holes are cut.........

 

[ritelec]

Thank you George Stolz....I'm doing a happy dance on the smokes right now.....

The pancake... I think I may get thru that..
They still make bx right (ac)............2nd floor bed, splice nm to bx (attic).... bx to the pancake (fancake) 6 cu in. and grounded.

Thanks again.
Rich

That was to say, I'm styling now for the smokes using the nm and plastic old work round box on the ceiling..........

The pancake/fancakes are for lighting and fan/lights.......which would need to be ac.

 

[George Stolz]

Between framing members:

http://www.newegg.com/Product/Product.aspx?Item=9SIA0ZC0AC3155

On framing members:

http://www.alliedmoulded.com/index....egory/template/products_sub_res/categoryid/47

 

[ritelec]

:thumbsup: thanks George