electricallight-fixturelighting
I am a first time homeowner. I removed old light fixture and will be installing a heavier 35 lb chandelier. Will this box hold the weight? I see two torx head screws about 2.5-3 inches long screwed into something hard. Not sure if it is a stud or a ceiling joist. Please see photo
The box does not wiggle when I pull on it but I am only 105 lbs and not too strong.
WIll this box hold a 35 pound light fixture?
From what I could find, it doesn't look like these types of boxes are listed for any type of fixture support.
When looking at a box that attaches to a stud/joist using nails (B520P), it states.
Suitable for fixture support up to 50 lbs.
With the the old work version(B618R), it states.
Not listed for fixture support in ceilings.
A box like this (BH614R), states.
Listed for wall fixture support up to 10 lbs.
The last page of this catalog shows some round boxes, and the weight they are rated to hold.
Based on this information, I would say the box you want to use will support less than 10 lbs.
The best options in your situation, would be to move the fixture location to allow you to fasten the box to a structural member, or add a structural member to mount the box to.
I contacted a company that manufactures these, and here is their response.
[Link to product omitted]
As shown on the link above this item is not listed for fixture support. We do have several other boxes that are rated for fixture support.
[Link to other product omitted]
The link for boxes rated for fixture support, pointed to boxes that attached to structural members.
If you can get enough access to install a BX connector on that armored cable, and if you can establish that the armor is actually a good protective ground (some armored cable only "floats" electrically), then you may be able to use a "remod box" to connect to the BX and claim your ground from the box. If none of those is true, then you really should do whatever it takes - cut access holes to be covered by the tracklight and install 2x4 remod boxes, whatever - to at the very least finish up that run with NM-B (Romex-type) cable. Given that this is for an overhead tracklight and you may not have any true grounds anywhere on that whole floor, and this house was probably wired long before grounding light fixtures became standard, you're probably legally covered.
I'm not as worried about spark containment as I could be, since the tracklight has its own termination box. Chafing of the wire insulation, though, is a bit worrisome; that's the largest reason for NM-B becoming standard. At the very very least, it'd be good to strip (without splitting) the outer sheath from a length of new NM-B and pull your two individual wires through it.
Best Answer
If the screws are course thread and driven solidly into the ceiling joist the box should hold your luminaire without a problem.
You could test it by hanging 35 pounds of weight from the fixture strap for a few days.
Standard ceiling boxes are manufactured to hold up to 50 pounds if they are solidly installed.
Here is the pertinent National Electrical Code Article:
That is a "pancake" box so your fixture should have a canopy that adds more volume for the wire connections since there is not very much room in that box.