ECN Forum Forums General Topics of the Trade General Discussion Area What kind of boxes do you use for fixtures?

What kind of boxes do you use for fixtures?
Wall mounted or ceiling mounted.
Do you use round, octagon, etc and Metal or plastic?


Bill

I actually ran into trouble installing (old work) wall sconces. I cut the hole for a round old work box, but the round sconce base didn't completely cover the flange on the round old work box. I had to install rectangular box and patch the remaining holes on each side. Luckily, no wall paper.

I'm still experimenting, my last effort was 3/4" pancakes with a shim behind to match the 5/4" blocking of outside wall lighting.

I entered the wire thru the clamp ko , so that the box could be unscrewed from the wall and rotated slightly to accomodate siding situations.

plastic is fast, but metal has it's attributes.

For fixtures I prefer metal in finished ceilings. Outdoors on siding, I prefer plastic Arlingtons old work. Looks neater.

plastic is fast, but metal has it's attributes.

I had a bad experience a few years back with a Carlon nail-on round box for a ceiling fixture.

After the rough-in the customer decided that they wanted a chandelier. Since the fixture was not particularly heavy we hung it from the plastic box.

About a year later we were called out to the house.....the fixture was laying in the middle of the dining room table! While replacing the box I noticed that the plastic was very brittle, unlike a typical new plastic box. No signs of high heat or other problems.

Now, if there's any chance for a large fixture. I use metal at rough-in time.

GJ

GJ,

I'm with you on that! Any rooms or Foyers that may get a heavy fixture would get a metal box or a Fan-type box/support.

Sparky,

I too like the pancakes as they can be cut into the siding afterwards when fixtures are available and final positioning can be determined.

Question:
are you technically allowed to hang a fixture off of a 3 x 2 Device Box?


Bill

I was getting ready to ask that myself...

I often wondered if "ceiling" boxes were allowed on the wall, and/or if device boxes were allowed to have (sconce) lights, (code loop?) My supplier lists round PVC nail-ons as "ceiling" boxes, but I don't know if they're saying that for their own purpose, or have extracted it from the product description...

I use adjustable bar hangers and octagonal boxes for vanity lights (I like the adjustability for lining up with the vanity CL), although the bar hangers are called "ceiling bar hangers" according to the supplier description, once again...

Aren't boxes supposed to have at least two points of attachment? Bar hangers only attach at one point...

(My NEC is in the truck, 175' away at the bottom of the hill at the end of my driveway... gimme a break!)

I've used device type mason boxes in brick for lights, to avoid having to special order octagonal mason boxes.

As far as device boxes, would tapping the mounting tabs out to 8x32 make a difference?

'66

If you notice, device boxes use 6/32s and Fixture boxes use 8/32s.

Are 8/32s considered necessary for fixture support somewhere? I think we've all used device boxes for support of wall fixtures at one time or another. Personally, I wish that all fixtures had a common shape and size mounting base, but that's never going to happen. Especially in the land of Interior Decorators. Did you ever use those 1 x 3 Boxes?

Bill

UL White Book, under "Metallic Outlet Boxes".
[quote]Fixture Support. A box, with or without bracket or bar hanger intended for the support of a fixture is provided with a marking "FOR FIXTURE SUPPORT" on the carton to indicate that the box is for fixture support. Metallic device boxes and device plaster rings have not been investigated for the support of a ceiling fixture unless marked to indicate such use. Metallic device boxes or a metallic device boxes intented to be installed in an existing structure have ben investigated for teh support of fixtures, smoke detector, carbon monoxide detectors weighing not more than 15 lb.[/b]
The same wording using the word nonmetallic in place of metallic appears in under the heading "Nonmetallic Outlet Boxes".
It appears to me that unmarked device boxes are not suitable for ceiling fixtures, but can be used for wall fixtures less than 15 pounds.
Don(resqcapt19)