I spent the weekend helping my Dad prepare his house to be put on the market.
One of the tasks was to remove the light fixtures from a bathroom. After removing the fixtures themselves, I was left with the mounting plates shown in the following picture.
formatting link
When I removed the plates I found that the electrical boxes were not attached to the studs, instead they were attached directly to the back of mounting plates using a threaded tube and strap, similar to this setup:
formatting link
The threaded tube came through a hole in the center of the mounting plate and was secured with a nut. The mounting plates themselves were screwed through the wallboard into a stud. Obviously, when I removed the plates, the electrical boxes came out with them.
It looks like the fixtures were intended to be installed that way, they had knockouts to accept the cable or conduit connector and space for the wiring junction to be made. If it was not acceptable, seems odd the fixture would have been designed and listed that way.
The strap and threaded tube is a standard mounting system for most light fixtures. However, the box itself should have been secured to the wall in some way, even without the light strap.
If you can't secure the box to a stud, the easiest option would be to pick up a "remodel" style box. These typically have a flange on the front and tabs of some type that swing out from the back to secure the box to the drywall.
That said, if your light fixtures have any signficant weight, you should really find a way to secure the box to a stud for support.
The holes where the wires came through were actually rimmed with a brass ring to prevent the steel from damaging the insulation. I don't recall that that there were knockouts for conduit connectors. Romex connectors were used in the box itself.
The hole for the threaded tube was dead center, but we don't know that that meant the box did not need to be secured. It may simply have meant that the plate could easily be mounted to the box, not vice-versa.
In addition, we don't really know if it was "listed" to be installed that way. I was removing the fixtures, not installing them, so I don't have instructions to refer to.
Thanks for all that, although it wasn't really a "how to" question. It was more about whether or not the method used was an acceptable method.
That said, the thickness and size of the steel plate and the fact that it w as screwed to the stud with big honking screws gave me no concerns about th e support of the fixture and electrical box. A couple of screws through the side of the box itself or tabs to support the box against the back of the drywall would merely be adding suspenders to the belt. Trust me, those moun ting plates (and therefore the electrical boxes) weren't going anywhere.
First impression was to say, "No". Boxes want to be secured, Romex wants to be anchored to a stud near its entrance into box, etc.
But, after thinking about it, ceiling (exhaust) fans are constructed the same way: box is part of fan and supported by the fan. The same is true of "remodel" style recessed can lighting. etc.
So, probably would get past a reasonable inspector. OTOH, you may want to change the installation going forward.
I was going by the second pic that shows the backside nut of what looks like a normal conduit connector fastened to a metal box.
Either type fits in the same 1/2" hole. The point was that if the fixture has knockouts then it sure looks like it must have been designed and listed for use that way.
You;ve lost me now. What I thought you had was a mounting bracket that also served as a junction box, it was secured to the wall.
It would seem the main issue now is not what was there, but what are you replacing it with? If you're replacing it with the typical light fixture that mounts to a box, then as others have suggested, put in one of the round old work boxes that use ears behind the drywall. Unless the new fixture is too heavy for that.
Note the words "electrical boxes...attached directly to the back of mounting plates using a threaded tube and strap".
I then included a picture of an electrical box with a threaded tube and a strap.
Insert the tube through the mounting bracket, secure it with a nut, and you have an "electrical box...attached directly to the back of mounting plates using a threaded tube and strap".
2 separate objects attached together, not a mounting plate that serves as a junction box.
If what was there is what I am replacing it with, then it's still an issue.
Everything was removed so that the wallpaper could be stripped, the walls repaired and painted. We may very well replace all of the same fixtures. If that is the choice, then I want to know if the original installation method is acceptable so I just put it back in.
We have not reached that decision point yet. That is why my post was not a "How I do I mount an electrical box for a light" question. My question was (and still is) is whether or not the original installation method was acceptable.
If it's not, I have no problem coming up with a way to secure the box to the wall and then the plate to the box. However, there is no need for me even to think about that if the original method is OK.
In that case, didn't GFRE give you the answer? He said as long as the boxes are securely mounted, it's to code, ie that it's acceptable that they are mounted to the brackets with are in turn securely mounted. But the typical new lights I've seen for use in that kind of location, don't mount that way. They rely on the box holding the fixture.
There may never have been a rough or a final. This house was built by my grandfather in a small Massachusetts town. Grandpa was a mason who laid many of the millions (?) of bricks for the paper mills along the Connecticut River in Holyoke, MA. I'm sure you know how things were done back then. There may have been permits, there may not have been, but I'm pretty sure there weren't any real, formal inspections.
[When my Mom was in grade school Grandpa started building a new house for his family. (not the one we're discussing here) He ran out of money after building the basement, so he sold the house they were living in and they moved into the basement of the new place. Over the next year or so, he and other family members built the rest of the house above them. I'm pretty sure that wasn't "allowed', even back then, but many things were ignored, depending on who you knew. (Just like today, I guess)]
Aside from that, the fixtures are not even close to original, so even if whatever was there before was inspected and passed, this installation was done some time long after the house was built.
Thanks for the answer. It we reuse the fixtures, I'll put it back together the same way.
+1 on the end result; with those mounting straps as furnished it's the logical way.
As your followup notes; in all likelihood there was no inspection in play and these followed well after any, any way. The requirement is a solid fastening, not any specific fastening, per se. IOW, it's the end result not the method.
As for the "living in the basement while building the house", the grandparents here built two halves of the eventual granary on either side of a driveway as the first structures on the place when homesteaded. They lived in the west half, used the east as the barn for two year or so at which time the basement for the house was dug and covered by the first floor subflooring and a layer of tar paper.
They then moved from the barn to the basement and lived there while the rest of the house was built. This was ca 1914-1916+. My father was first of the children born in the house; he used to joke he was born in the coal room as that is what the area of the original basement became when the initial furnace was installed for the main house. Was _very_ progressive for a farmhouse in SW KS at the time; was wired for and installed a Delco windcharger system at the time...
"When I removed the plates I found that the electrical boxes were not attached to the studs"
I got the impression the box was just "floating" somehow other than the front strap for the fixture mounting. I couldn't see a mounting bracket in the photo, but maybe it's there in the bottom of the hole?
Either way, as long as the box is secured somehow, you should be fine.
I still don't understand the installation, even after seeing the photo.
If you remove that front diagonal strap, is the box loose in the wall? If so, that is not a normal installation. As long as the box is secure when everything is tightened down, it shouldn't matter. But thinking ahead to future fixture replacements that may have different mounting systems, I would find a way to secure the box without the front strap.
I can see how it might be hard to understand from the pictures, so I'll explain it in a different way.
The following picture of a junction box is an *example* of how my dad's junction box is configured, including the strap and threaded tube. Imagine that it is not attached to the wall in any manner. The wires are secured to the box with Romex connectors, but the box, with the strap and the threaded tube, could fall into (or out of) the wall.
formatting link
First, remove the nut from the threaded tube and set it aside.
Second, grab the fixture mounting plate and feed the wires through any of the larger holes in the plate *except* for the hole in the exact center.
Third, locate the hole in the exact center of mounting plate and slip it over the threaded tube then secure it with the nut that you removed earlier. The junction box should now be firmly attached to the back of mounting plate, but nothing is yet attached to the wall.
Fourth, slip the junction box into the hole in the wall until the mounting plate is flat against the surface. Locate the 2 smaller holes in the plate and drive screws through the holes into a stud behind the wall board.
You now have a fixture mounting plate firmly attached to a wall support, a junction box firmly attached to the back of the mounting plate, and the Romex firmly attached to the junction box.
Fifth, grab the fixture itself and properly connect all wires.
Finally, slip the fixture over the mounting plate and secure it with the screws provided.
Basically, I have no concerns that the installation was unsafe in any manner since everything was solid and secure. I just didn't know if the box itself should have been attached to the wall before the plate was attached.
I guess it's not much different than a ceiling fan. The junction box for a ceiling fan is part of the fixture housing. The Romex is attached the junction box with Romex connectors and then the housing is attached to the framing.
In this case, the junction box didn't come as part of the fixture, but in the end, once it was connected to the mounting plate, it really wasn't very different than the ceiling fan situation.
However, I can see how a rough inspection would have been an issue. Until the plate is secure to the wall, everything is just hanging there. That wouldn't pass. However, once the plate is secured to the wall, you can no longer see the junction box to inspect it.
In the situation that started this thread, by having the junction box attached to the mounting plate and then having the mounting plate screwed to a stud, the fixture is much more secure than it would be if the junction box was held in by a couple of tabs.
The mounting plate is pretty thick and the fixtures have some heft. The torque on the tabs would be significant.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.