light fixture support, and code compliance in commercial applications

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in commercial applications:
When does a fixture need to be supported from structure?
What constitutes structure?
of consequence, are remodeler housings, that merely attach to gyp. bd. or ACT code compliant?

Which leads to the real question:
Many LED fixtures are now being provided without a housing, consequently the only means of support is in the "remodeler style"; is their installation code compliant?
Some have a "frame" accessory; is this necessary for compliance, or is it merely a convenience to the installation?

such as: http://www.prescolite.com/products/a2led

with many thanks in advance,
Mark
 

JFletcher

Senior Member
Location
Williamsburg, VA
We put in these or something similar in drywall quite a bit:

http://www.build.com/lithonia-light...2799!&ef_id=VdlGLgAAAZFJz@Yf:20151020214946:s

Dont quote me on this, but afaik in commercial new construction you're not going to have cans like that. What is installed has to be tied off/nailed to the structure (ceiling or joists) and the lights cannot be solely supported by things like the ceiling grid.

On pg 17 of the PDF from your link, it shows them being mounted in drywall as old work:

http://cdn.prescolite.com/content/products/literature/literature_files/pr1083_2inled_brochure.pdf

I cant imagine Prescolite and Lithonia both selling a product that, installed as shown, would be a violation of the NEC.

eta: the frame accessory is for installing those kinds of lights in new construction
 

JFletcher

Senior Member
Location
Williamsburg, VA
For what it's worth the people who make Sheetrock say not to use ceiling mounted Sheetrock to support anything.

Bob, do you have a link to said limitations? All I found was off a USG site, which stated "Limitations:... 3) Non load bearing". I guess a 1lb light could be considered a load, but I refer back to any old work box/light of any type by their manufacturing specs. Is Lithonia, etc. violating the sheetrock manufacturers specifications with old work cans?
 

mgookin

Senior Member
Location
Fort Myers, FL
For what it's worth the people who make Sheetrock say not to use ceiling mounted Sheetrock to support anything.

Post hurricane Andrew we had a structural debate on why the code allowed the engineer to consider the sheetrock on the bottom cord of the roof trusses as contributing to the diaphragm to resist wind forces and the answer was, because if the roof is gone and letting water compromise that sheetrock, you're toast anyway.

I know fire departments don't want to rip out ceiling tiles or sheetrock and have light fixtures fall on their head.

Where is any of this in today's code? I don't keep up on it. Just thought I'd throw those things out there for consideration.
 

JFletcher

Senior Member
Location
Williamsburg, VA
I know fire departments don't want to rip out ceiling tiles or sheetrock and have light fixtures fall on their head.

Where is any of this in today's code? I don't keep up on it. Just thought I'd throw those things out there for consideration.

Old work boxes and lights are made. Blown in insulation is common. Ceiling tiles or grid cannot, tmk, support anything other than the tiles. That said, even a nailed-in fixture or box is going to lose to a fire axe. If a fire was suspected above, say, a surface mounted 4' fluorescent light troffer, would it really matter if said troffer was attached to the above floor/ceiling joists or butterfly bolted to the sheetrock? Either way, it's coming down.

In my experience, in commercial work, you can usually tell if the lights are just set on the ceiling tiles w/o being supplementary supported; the tiles are horribly bowed/dished from the weight in a short time (<3 years). To me, this is a serious life and safety code violation.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
From the 6th edition of the "Gypsum Construction Handbook".
Gypsum boards used in the ceiling are not designed to support light fixtures or troffers, air vents or other equipment. Separate supports
must be provided.
 

iwire

Moderator
Staff member
Location
Massachusetts
I can see this applying to sheet metal or flex supply ducts, but would a simple flat return air louver into an environmental air space need to be separately supported too?

Typically those ducts are roughed in place ahead of sheet rock and the grills are screwed to the ducts after all the finish work is done.
 
and of consequence to the many conjectures...
What is the code?

Today's led fixtures can be significantly lighter, as little as 2lbs is common.
At this very moment, I have in my hand, one that is under 8oz. Does it need to be attached to structure ?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Typically those ducts are roughed in place ahead of sheet rock and the grills are screwed to the ducts after all the finish work is done.
I was specifically asking about the vent louvers or grilles without any duct work.
But I guess most of those are full tile size assemblies that are supported by the t-bar, possibly with additional wires even though some weigh less than the times they replace.
 
I'm not getting the relevance between HVAC and light fixtures;
I see a parallel, yet the 2 are different. My query is (implicitly) specific: "What does the code say, and what have been its interpretation on the support of (overhead) lighting fixtures and their attachment to structure?"

As with many things sometimes the simplest can be the most evasive -sigh
 

iwire

Moderator
Staff member
Location
Massachusetts
I'm not getting the relevance between HVAC and light fixtures;
I see a parallel, yet the 2 are different. My query is (implicitly) specific: "What does the code say, and what have been its interpretation on the support of (overhead) lighting fixtures and their attachment to structure?"

As with many things sometimes the simplest can be the most evasive -sigh

:?

The quote in post 7 directly states light fixtures, you are asking about a light fixture.

There is no NEC code on this but I suspect the building inspector could enforce the instructions from the drywall makers.
 

north star

Senior Member
Location
inside Area 51
& & >


" I'm not getting the relevance between HVAC and light fixtures;
I see a parallel, yet the 2 are different. My query is (implicitly) specific:
"What does the code say, and what have been its interpretation on the
support of (overhead) lighting fixtures and their attachment to structure?"

As with many things sometimes the simplest can be the most evasive ":
As with a lot of the various components & systems in buildings and
structures, there is a lot of gray area that is not specifically
stated in the various codes somewhere.........In this case, ..IMO,
it is the responsibility of the installer, or RDP to go and find out,
...to have a definite decision on the matter.............To accomplish
this, the installer, or the RDP should contact the Building Official,
or the Fire Code Official, or both, to request a ruling on the
matter.

Here's the "charging language"............
From the `12 IBC,Section
1604.2 - Strength:

"Buildings and other structures, and parts thereof, shall be
designed and constructed to support safely the factored
loads in load combinations defined in this code without
exceeding the appropriate strength limit states for the
materials of construction............Alternatively, buildings
and other structures, and parts thereof, shall be designed
and constructed to support safely the nominal loads in load
combinations defined in this code without exceeding the
appropriate specified allowable stresses for the materials
of construction.

Loads and forces for occupancies or uses not covered in
this chapter shall be subject to the approval of the building
official".


Again, ...IMO, if a question about any aspect of a project
arises, it is the responsibility of the installer, or the RDP
to go and find the correct answer...........Even if there is not
a specific code section somewhere, the installer or RDP,
can go to the BO to obtain a formal ruling on the matter.
If the installer or RDP does not agree with the [ written ]
ruling, ...then they can go thru an appeals process.


Mr. Kubicki,

Have you obtained a formal \ written ruling on your
question about the lighting product in question ?

Also, ...
**don_resqcapt19** has already provided part
of correct answer.


Thanks !


< & &
 
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