100 plus pound light

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splinetto

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What is the best way to support a 100 lb or even 400lb light. I have been told to run lag bolts up into wood bracing through the fixture strap or to use all thread through the center of a box into wood with nuts, washers , and a coupler in the box to accept the fixture nipple. Whats the best way?
 
A 100 pound plus fixture is going to come with a substantial fixture strap that will clear the box on both sides so that you can run lag bolts up into existing framing or framing/blocking that you provide. Some even come with a special back box. Just sorta depends on the fixture.
 
I hope the structure is capable of supporting an additional 400 lbs. For instance, I wouldn't want to support a 400 lb fixture from roof trusses, without some OK from an engineer.
 
If I were to install a 400 lb fixture I would talk the HO into a motorized lift if the fixture were up high. Otherwise I would call the manufacturer for their requirements

unionlighting_1957_20704654



I have used a fixture hickey (crow's foot, fixture stud) for lighter 100 lb fixtures

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Alright, I'm gonna do something stupid:

There's definately a difference between ceiling joists and roof rasters. Which these are isn't mentioned. I'm guessing joists though.

If I can put a waterbed on top of ceiling joists why should I be so paranoid to the point of needing an engineer to put a few hundred pounds on two joists?

Not that I might not have the same concerns, because I would definately want to be confident in the mounting apperatus. But calling in engineers, I'm just not seeing that in this case.

I'd just want to be sure the mount's sufficent.
 
Dennis Alwon said:
I have used a fixture hickey (crow's foot, fixture stud) for lighter 100 lb fixtures
Click to expand...

Speaking of 5/8ths and oxymorons ....how can a 100# fixture be a "light" 100#'s?

Isn't a ton of bricks the same as a ton of feathers :grin:
 
The trusses are TGI's or also called silent floors..They are not solid 2X6 so that is also a concern. The other one is that the light is on the 2nd floor ceiling and there is a 3rd floor above it. So I wont be able to crawl up in the attic to add more bracing / all thread if needed.. Drywall repair:grin:
 
I guess I'd probably like to know if this is a 100 pound fixture or a 400 pound fixture? The 100 pounder... I'd just add blocking out the wazoo during the ruff in. For a 400 pound fixture, I wounldn't do squat without a detail print from an engineer.
 
I just started an install of a 256 LB fixture, the structure has trusses already installed, so I found a copy of the original prints and am asking the building inspector for advice, not exactly sure what the outcome will be... so stay tuned... I plan on cutting the ceiling open on Monday, I had to rent a lift because of the ceiling height, 27' from floor to ceiling, this is a real PITA...
 
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Physis 3 said:
If I can put a waterbed on top of ceiling joists why should I be so paranoid to the point of needing an engineer to put a few hundred pounds on two joists?
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The weight of the waterbed is SPREAD over a much larger area. The fixrure will be hanging from one small spot.


I would avoid VERITCAL lags. A horizontal fastener is stronger. Thru bolt if you need to go vertical. Try to spread the load between joists with backing. The more joists you can cross, the more you spread the load.
 
When I'm walking in an unfinished attic, I'm placing >300-pound weight in a <1-sq-ft area, and the joists hold me just fine.
 
My thoughts echo many of the other posts. I would get an architect or engineer involved. To put it simply, let them design the "method" of support and mounting. This way if something should happen you have CYA.

Pete
 
Dennis Alwon said:
Isn't the term



an oxymoron.

I have been called 5/8 of an oxymoron before---:grin:
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become an inspetor and you can be called certain direct oxen (and horse) body parts.
 
JohnConnolly said:
The weight of the waterbed is SPREAD over a much larger area. The fixrure will be hanging from one small spot.
Click to expand...

I had considered that before posting a reply. The waterbed also weighs tons though too.

JohnConnolly said:
I would avoid VERITCAL lags. A horizontal fastener is stronger. Thru bolt if you need to go vertical. Try to spread the load between joists with backing. The more joists you can cross, the more you spread the load.
Click to expand...

I agree entirely with you here. Distributing the load is what should be done and horizontal fasteners are a far better method than vertical.

Larry Fine said:
When I'm walking in an unfinished attic, I'm placing >300-pound weight in a <1-sq-ft area, and the joists hold me just fine.
Click to expand...

That's another thing I was also thinking. But >300#s, wow Larry. :grin:

I don't, but maybe somebody else knows the load capacity of a 2X6, the length would be a factor too though.
 
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