suspend ceiling luminair support

stephena

Member
Location
oregon
410.36B states suspended ceiling USED to support a luminair shall be secured......
so if my luminairs are being supported by guy wire then I'm not using the ceiling grid as a support system so therefore wouldn't have to secure luminair to suspended ceiling with screws or other approved machanical means. am i interpretting this right?
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
410.36(B) can be a little confusing but, if you skip the first sentence it becomes clear. The first sentence is basically trying to tell ceiling contractors how to install a ceiling system and should not be in the article section.

The rest of 410.36(B)) is our part and it does instruct us to fasten luminaires to the grid.

Roger
 

stephena

Member
Location
oregon
410.36(B) can be a little confusing but, if you skip the first sentence it becomes clear. The first sentence is basically trying to tell ceiling contractors how to install a ceiling system and should not be in the article section.

The rest of 410.36(B)) is our part and it does instruct us to fasten luminaires to the grid.

Roger
So you don't think the first part of the sentence saying "if used as support" doesn't give us leeway to not fasten it to the ceiling grid if we are using guy wire as the support system?
 

Smart $

Esteemed Member
Location
Ohio
So you don't think the first part of the sentence saying "if used as support" doesn't give us leeway to not fasten it to the ceiling grid if we are using guy wire as the support system?
IMO you are correct. Where a luminaire is supported independently of the suspended ceiling, securing to the framing members is not required. YMMV with AHJ.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
So you don't think the first part of the sentence saying "if used as support" doesn't give us leeway to not fasten it to the ceiling grid if we are using guy wire as the support system?
Correct, not as it is writen. Whether I think that is the intent or not is another story.

The first sentence is describing how the grid must be fastened together and attached to the building if supporting luminaires, IMO the second sentence is stand alone as to telling us we must fasten luminaires to the grid. Maybe the intent is for the luminaires to support the grid. ;)

Roger
 

JES2727

Senior Member
Location
NJ
Correct, not as it is writen. Whether I think that is the intent or not is another story.

The first sentence is describing how the grid must be fastened together and attached to the building if supporting luminaires, IMO the second sentence is stand alone as to telling us we must fasten luminaires to the grid. Maybe the intent is for the luminaires to support the grid. ;)

Roger
Roger,
I disagree. 410.36 is titled "Means of Support". 410.36(B) applies to suspended ceilings when used as a means of support. So if the ceiling is not being used as support then nothing in that section applies.
That being said, I agree with you that the luminaires in question are required to be securely fastened to the grid (I just don't agree with your reasoning). Looking at the rest of 410.36, guy wires are not listed as a means of support. Therefore, if the luminaires are installed in a suspended ceiling and hung from wires, the ceiling is the means of support. The wires are neither required by the NEC nor approved for support.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
Now go to the suspended ceiling standards...."All lighting fixtures shall be positively attached to the suspended ceiling system." "Fixtures weighing more than 10 lbs but less than 56 lbs, in addition to the requirements outlined above, two No.12 gage hanger wire connected from the fixture housing to the structure above."

ASCE and CISCA.

410.36(B) says that luminaires shall be securely fastened to the ceiling framing member by mechanical means.
 
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Smart $

Esteemed Member
Location
Ohio
Is a suspended ceiling grid considered a framing member?
They are a framing member of the suspended ceiling system, which is the terminology used in the requirement, but the latter part of 410.36(B) first sentence implies they are not to be considered a building structure framing member.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
They are a framing member of the suspended ceiling system, which is the terminology used in the requirement, but the latter part of 410.36(B) first sentence implies they are not to be considered a building structure framing member.
That is correct. A suspended ceiling is not considered a structural ceiling. So the fixture need to be secured to the suspended ceiling framing members and the two required wires need to be secured to the structural ceiling (underside of the roof).

The Building Code does not address a lot of things any more, but instead points you towards the appropriate standards. You need to read these standards as they are the same as manufactures instructions. The problem is they are not cheap. A 15 page document my run you $45-$80 depending.
 

kwired

Electron manager
Location
NE Nebraska
Now go to the suspended ceiling standards...."All lighting fixtures shall be positively attached to the suspended ceiling system." "Fixtures weighing more than 10 lbs but less than 56 lbs, in addition to the requirements outlined above, two No.12 gage hanger wire connected from the fixture housing to the structure above."

ASCE and CISCA.

410.36(B) says that luminaires shall be securely fastened to the ceiling framing member by mechanical means.
How much does a typical 2x4 troffer weigh these days? I bet less then 10 pounds - especially since you don't find magnetic ballasts in them anymore.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
They may not, but I didn't put in the section about if it's less than 10 lbs you need one No.12 gage wire. Also depends on what seismic zone you're in. and don't forget that when the fire department goes in there, and starts tearing down the ceilings, they love when the fixtures don't come crashing down too. So basically anything in the ceiling needs at least one wire, some more and some like ceiling fans might need threaded rod.
 

kwired

Electron manager
Location
NE Nebraska
They may not, but I didn't put in the section about if it's less than 10 lbs you need one No.12 gage wire. Also depends on what seismic zone you're in. and don't forget that when the fire department goes in there, and starts tearing down the ceilings, they love when the fixtures don't come crashing down too. So basically anything in the ceiling needs at least one wire, some more and some like ceiling fans might need threaded rod.
JMO, but 12 gage steel wire is overkill to support 10 pounds, you likely rip a hole at attachment point of the thin sheet metal before you even come close to compromising the wire.

Nobody is ever very particular about supporting items in suspended ceilings around here, so I don't really know what is in any codes besides NEC. If I did work in some of the larger towns (like 10,000+ population) maybe I would run into more building code issues, for most part all I run into is state fire marshal on buildings with public access be it a small retail store, or a larger place of assembly. They generally focus more on finish ratings, and protection of egress routes, and sometimes make requirements that make absolutely no sense at all.

Had a small office building (new building) that happened to have full basement and wood framed floor over that basement. Basement was not public access area, and was just mechanical and storage area. Fire marshal wanted a one hour door on the basement stairwell, yet the underside of that wood framed wood sheathed floor was totally exposed. A fire in that basement would burn a hole in the floor long before threatening the location of that one hour door unless it started right in the stairs maybe:slaphead: I thought if he was going to require the one hour door he should have at least wanted a one hour rating on the basement ceiling as well.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
JMO, but 12 gage steel wire is overkill to support 10 pounds, you likely rip a hole at attachment point of the thin sheet metal before you even come close to compromising the wire.

Nobody is ever very particular about supporting items in suspended ceilings around here, so I don't really know what is in any codes besides NEC. If I did work in some of the larger towns (like 10,000+ population) maybe I would run into more building code issues, for most part all I run into is state fire marshal on buildings with public access be it a small retail store, or a larger place of assembly. They generally focus more on finish ratings, and protection of egress routes, and sometimes make requirements that make absolutely no sense at all.

Had a small office building (new building) that happened to have full basement and wood framed floor over that basement. Basement was not public access area, and was just mechanical and storage area. Fire marshal wanted a one hour door on the basement stairwell, yet the underside of that wood framed wood sheathed floor was totally exposed. A fire in that basement would burn a hole in the floor long before threatening the location of that one hour door unless it started right in the stairs maybe:slaphead: I thought if he was going to require the one hour door he should have at least wanted a one hour rating on the basement ceiling as well.

You would think.

Well it's like a lot of things we talk about in here, sometimes it just depends on where you live. If you had lived here after the '94 earthquake you would be glad that there were tie wires on those fixtures. :happyyes:
 
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