3

I want to know if a drywall ceiling support hanging a 20kg chandelier

  • Do you mean without any attachment to bracing, just hanging from the drywall? – bib Mar 10 '16 at 12:11
6

No, not with just the drywall.

Fasten a bracket to the ceiling joists with some good lag bolts for that much weight.

The problem isn't today but 5 or 10 years from now. Will the light eventually weaken the drywall enough to break it?

Why take that chance with you and your family?

Good luck!

  • I'd argue that the problem is today. 50 pounds will likely pull the sheet right off the framing, if the anchors hold. – isherwood Nov 6 at 17:41
4

I know ceiling fans require a special box for that much weight. I would at a minimum add a cross brace to attach the box to similar to a ceiling fan for such a heavy fixture. sheetrock will not carry this much weight with a standard fixture box.

4

NO! Ceiling mounted drywall alone cannot support any significant weight.

There are several types of toggle bolts that have some degree of tension strength. For example, according to this chart from one of the toggle bolt manufacturers, a single toggle bolt can hold up to 50 lbs under a tension load.

toggler chart

Hilti Inc.

However, as @WolfHarper points out in a comment, those Togglers are rated for clearspan. In mounting a ceiling fixture, they'd be bolting near the edge of a big hole made for the junction box. This drastically reduces the strength of the drywall (and consequently the toggles in the drywall) Further, how is the drywall attached to the joists? The drywall may begin to deteriorate or pull away from the joists, especially if it is nailed instead of screwed.

ALMOST NO EXPERIENCED DIYER OR PROFESSIONAL WOULD RECOMMEND THAT YOU DO THAT! AND VIRTUALLY EVERY ELECTRICAL INSPECTOR WOULD REJECT SUCH AN APPROACH!

The risk is huge. A falling ceiling fixture can be fatal. Ceilings are prone to flexing and shaking from traffic on the floor above, Drywall can be fragile stuff, easily compromised around mounting holes.

There is a fairly easy safe solution, a fan brace

fan brace

These are retrofit devices. A hole the size of the junction box is cut into the ceiling drywall. The brace, which detaches from the box for mounting, is inserted into the hole and then expanded until it grips two of the framing members (joists) in the ceiling. The box is then remounted on the brace.

These are designed to support fixtures up to 150 lbs. and fans up to 70 lbs.

 Images and links are for illustration only, not an endorsement of goods or sources.
  • Not even theoretically. Those Togglers are rated for clearspan. Here they'd be bolting near the edge of a big hole made for the junction box. Even so, how is the drywall attached to the joists? Anyway, if they plan to run electricity to it, NEC and the inspector will drag them kicking and screaming to an on-joist mounting. That's no problem; NEC foresaw this with 314.27A2, which amounts to a product spec, along with 314.27C, a better product spec, which is your fan-brace above. – Harper - Reinstate Monica Mar 11 '16 at 18:40
  • @WolfHarper Excellent point. I will add your info to the answer. – bib Mar 11 '16 at 19:02
  • By the way, your link is wrong (doesn't match your image/prose), it goes to a product intended only for new work. Check out this one in Herrbag's answer. diy.stackexchange.com/questions/26873/… – Harper - Reinstate Monica Mar 11 '16 at 19:26
  • Question: if an electrical box is firmly screwed to a ceiling joist, can one get buy without the fan brace? That is, is the brace only needed when fixture falls between two joists, or to meet code would one have to relocate an existing box to the brace, opening a new hole in the ceiling and patching the old one? – keshlam Mar 11 '16 at 20:26
  • Also, re falling fixtures: Fans certified for sale in California come with a safety cable, intended as a backup if an earthquake shakes the primary mounting loose. That's worth installing anywhere, though. – keshlam Mar 11 '16 at 20:34

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