Outlets - suspended ceiling

[Chukster]

OK, involved question here:

We're renovating a downstairs into an apt for our adult daughter (who works full time 2nd shift at a good job, but trying to find a rental at a decent price AND run the risk of roommate lottery - no).

Ceiling is standard suspended acoustical tile, and we'll be replacing it with and Armstrong product, "Easy-Up" which is a tongue-n-groove plank and goes up to ceiling grid with clips, no screws except at the walls.

One end of the room is a brick-faced fireplace (unused, we'll probably put a small electric 'showpiece' in there) There's space for a TV between the mantel and the ceiling. Question is the power and signal wires.

Does code allow an outlet box above the ceiling? Or should I stick with an outlet box trimmed into the ceiling?

If we can do a box above the ceiling, I will trim out an opening in the ceiling for power and signal wires, and maybe make a wide u-channel on the bricks to bring the wires to behind the screen. I figure to use some leftover ceiling planking for the channel. Signal cable will go over to the side wall, and to electronics on a shelf.

Gas piping you can see feeds the logs on the living room upstairs. Any problem with it being that close?

 

[930dreamer]

I have outlets in the attic so....

 

[SarcasticDwarf]

Does code allow an outlet box above the ceiling? Or should I stick with an outlet box trimmed into the ceiling?

Above a suspended ceiling? My understanding is they are allowed only for rare use, which means that you can't have anything plugged in long-term. So no lights, tvs, etc. This was a relatively recent change to the electrical code.

 

[wyliesdiesels]

OK, involved question here:

We're renovating a downstairs into an apt for our adult daughter (who works full time 2nd shift at a good job, but trying to find a rental at a decent price AND run the risk of roommate lottery - no).

Ceiling is standard suspended acoustical tile, and we'll be replacing it with and Armstrong product, "Easy-Up" which is a tongue-n-groove plank and goes up to ceiling grid with clips, no screws except at the walls.

One end of the room is a brick-faced fireplace (unused, we'll probably put a small electric 'showpiece' in there) There's space for a TV between the mantel and the ceiling. Question is the power and signal wires.

Does code allow an outlet box above the ceiling? Or should I stick with an outlet box trimmed into the ceiling?

If we can do a box above the ceiling, I will trim out an opening in the ceiling for power and signal wires, and maybe make a wide u-channel on the bricks to bring the wires to behind the screen. I figure to use some leftover ceiling planking for the channel. Signal cable will go over to the side wall, and to electronics on a shelf.

Gas piping you can see feeds the logs on the living room upstairs. Any problem with it being that close?

the short answer is no because cordage is not allowed above suspended ceilings.

Back when i did McDonalds remodels we had to remove and extend any outlet circuits terminated above the drop ceiling down to the ceiling.

Also. NM-b is not allowed above a drop ceiling either. So you will need to use MC or AC to extend these circuits...

EDIT: NM-b is allowed above suspended ceiling in one and two family dwellings only...

I have outlets in the attic so....

not the same as a suspended ceiling

 

[Pingel85]

Flexible cables are not allowed to be concealed above suspended ceiling. Code allows for an outlet up there, but you're not allowed to plug your tv in, since the cord would be above the ceiling.

 

[Pingel85]

the short answer is no.

Back when i did McDonalds remodels we had to remove and extend any outlet circuits terminated above the drop ceiling down to the ceiling.

The issue is you cannot have cordage above the ceiling

Also. NM-b is not allowed above a drop ceiling either. So you will need MC or AC.



not the same as a suspended ceiling

Last I checked, nm was allowed above suspended ceiling in 1 and 2 family dwellings.

 

[wyliesdiesels]

Last I checked, nm was allowed above suspended ceiling in 1 and 2 family dwellings.

I stand corrected.

334.12(A)(2) NFPA 70/NEC 2020

 

[Norcal]

Was pretty common locally in small office buildings to use NM above suspended ceilings until disallowed by the NEC, and I agree that receptacles are prohibited above a suspended ceiling.

 

[Chukster]

Thanks for the answers.

Now I apparently have to disabuse the wife of the idea that the TV will be completely wireless and will not need any signal cables at all. Ever. Forever and ever, Amen. Therefore no need for any sort of signal cable provision.

 

[alfredeneuman]

Outlets are allowed above a suspended ceiling but cords aren't.

 

[grounded-b]

Outlets are allowed above a suspended ceiling but cords aren't.

This is correct.

An outlet may be REQUIRED to be above a suspended ceiling, if there is an HVAC air-handling device, which requires service. This would be for temporary use.

Flexible cords are not allowed to be above a suspended ceiling, nor pass through a suspended ceiling.

Steve

 

[reader2580]

Back when i did McDonalds remodels we had to remove and extend any outlet circuits terminated above the drop ceiling down to the ceiling.

Also. NM-b is not allowed above a drop ceiling either. So you will need to use MC or AC to extend these circuits...

Is NM-B allowed in commercial buildings? I always thought that commercial requires metal conduit of some sort. I was in my employer's new office space numerous times during construction and everything was either MC or EMT.

 

[grounded-b]

Is NM-B allowed in commercial buildings? I always thought that commercial requires metal conduit of some sort. I was in my employer's new office space numerous times during construction and everything was either MC or EMT.

per NEC 334.10(3)
NM, NMC and NMS cables are permitted in other structures (commercial) if of type II, IV or V construction. Types of construction can be found in NFPA 220 or in Annex "E" of NFPA 90 ( the NEC )

Steve

 

[rsanter]

Above the ceiling, hardwired

Mounted into the ceiling for access in the room.....is fine

 

[wyliesdiesels]

per NEC 334.10(3)
NM, NMC and NMS cables are permitted in other structures (commercial) if of type II, IV or V construction. Types of construction can be found in NFPA 220 or in Annex "E" of NFPA 70 ( the NEC )

Steve

fixed it for ya. NFPA 90 doesnt exist and 90a is for air conditioning

 

[ripperd]

Throw up some 2x blocking and mount an outlet such that it is flush with the drop ceiling.

 

[Citation]

One of this things I like about this sub forum is getting to ask why the rules are what they are.

Based on the discussion above I'm curious about a few of the rules.

Why would MN-B be restricted in a suspended ceiling?
Why are cords/outlets not allowed in a suspended ceiling?

 

[alfredeneuman]

Why are cords/outlets not allowed in a suspended ceiling?

Because all cords rot with age to a certain extent they must be visible for their entire length (impossible above a suspended ceiling).

 

[Brandon_oma#692]

Because all cords rot with age to a certain extent they must be visible for their entire length (impossible above a suspended ceiling).

Makes a little bit of sense. So..... all the old TV's in the entertainment centers that blocked access to see the cord should be a similar violation?

 

[Noltz]

Throw up some 2x blocking and mount an outlet such that it is flush with the drop ceiling.

This was my initial thought too. Block it down, attach a 2 gang box and mount 2 outlets in it for four plugs available up there.

 

[AntonLargiader]

Makes a little bit of sense. So..... all the old TV's in the entertainment centers that blocked access to see the cord should be a similar violation?

Similar situation, but not similar violation if one is specifically prohibited by code and one isn't. I think a cord behind a drop ceiling is legitimately either inaccessible or a substitute for permanent wiring, whereas a tangle of cords in the back of an entertainment center is just normal utilization that is not in danger of being damaged.

 

[nadogail]

Just like the cords under the bed, they are barely accessible.

 

[alfredeneuman]

Makes a little bit of sense. So..... all the old TV's in the entertainment centers that blocked access to see the cord should be a similar violation?

Furniture doesn't count because it's not a part of the structure

 

[Norcal]

This was my initial thought too. Block it down, attach a 2 gang box and mount 2 outlets in it for four plugs available up there.

There are bar hangers specifically made for suspended ceilings to support boxes Caddy has a lot of options to fit the users needs but don’t go to a big box store for them, a legitimate electrical supplier will have them.

 

[alfredeneuman]

don’t go to a big box store for them, a legitimate electrical supplier will have them.

HD has them or at least had them a couple of years ago

 

[cybrdyke]

One of this things I like about this sub forum is getting to ask why the rules are what they are.

Based on the discussion above I'm curious about a few of the rules.

Why would MN-B be restricted in a suspended ceiling?
Why are cords/outlets not allowed in a suspended ceiling?

Fire and smoke. The material used emits noxious gases when burned.
CD

 

[Citation]

Fire and smoke. The material used emits noxious gases when burned.
CD

I get that. When I added some speaker wire run through the ceiling I used in wall rated speaker wire. But, what would make a ceiling space more sensitive to this vs any extension cord in my house? Is this a case where the electrical code can't force me to use a "safe" extension cord* but they can try to say where I can't use my unsafe cord?

*I'm assuming things like cords aren't governed by the same governing bodies but again, not an expert here.

 

[wyliesdiesels]

I get that. When I added some speaker wire run through the ceiling I used in wall rated speaker wire. But, what would make a ceiling space more sensitive to this vs any extension cord in my house? Is this a case where the electrical code can't force me to use a "safe" extension cord* but they can try to say where I can't use my unsafe cord?

*I'm assuming things like cords aren't governed by the same governing bodies but again, not an expert here.

suspended ceilings typically have air return ducts which are notorious for leaks and can **** up aforementioned smoke. Sometimes, suspended ceilings are used as plenums for the return air and thus the entire space above the ceiling is a duct. I have seen this in tall office buildings with central heat and chillers for air conditioning.

cordage and flexible cords are a chapter 4 wiring method in the NEC so yes they are governed by the same code

 

[97tj-neil]

We need to take a step back here and focus on proper TV mounting height. Above a fireplace is always too high for comfortable viewing, and always the wrong answer.

The center of the screen should be eye level when you are seated.

Here is some more info: https://www.hellotech.com/blog/how-high-should-a-tv-be-mounted

 

[Chukster]

We need to take a step back here and focus on proper TV mounting height. Above a fireplace is always too high for comfortable viewing, and always the wrong answer.

The center of the screen should be eye level when you are seated.

Here is some more info: https://www.hellotech.com/blog/how-high-should-a-tv-be-mounted

In an optimum world yes, you're right. But this will be the only place in the room big enough for a TV; the room is about 24L x 12 wide, there's no other large wall space. The next largest wall is an outside wall, occupied by a large double window, then the stove, door outside, etc etc. And this position will allow her to have the TV on for noise while she's standing in the kitchen area cooking & such.

 

[AntonLargiader]

That's amazing, that someone would want something like that on for the noise. I know it's a real thing for PTSD though.

 

[cybrdyke]

suspended ceiling typically have air return ducts which are notorious for leaks and can **** up aformentioned smoke.

cordage and flexible cords are a chapter 4 wiring method in the NEC so yes they are governed by the same code

What he said^^^
The area above a suspended ceiling is often an air return and burning materials in that space will quickly transfer poisonous gases throughout the building. This is how most people die in building fires.
CD

 

[Chukster]

That's amazing, that someone would want something like that on for the noise. I know it's a real thing for PTSD though.

It's kind of a thing for people with ADD/ADHD tendencies; a need for background noise to keep the other parts of the brain working where they should.

Ever been in a mechanic's shop that has a radio blasting, all day, same station, same playlist, same crappy reception and cranked to the max? Some people can't think in that situation and others thrive.

 

[alfredeneuman]

We need to take a step back here and focus on proper TV mounting height. Above a fireplace is always too high for comfortable viewing, and always the wrong answer.

What's that got to do with "Outlets - suspended ceiling"?

 

[AntonLargiader]

What's that got to do with "Outlets - suspended ceiling"?

Read the very first post.

 

[n8n]

suspended ceilings typically have air return ducts which are notorious for leaks and can **** up aforementioned smoke. Sometimes, suspended ceilings are used as plenums for the return air and thus the entire space above the ceiling is a duct. I have seen this in tall office buildings with central heat and chillers for air conditioning.

cordage and flexible cords are a chapter 4 wiring method in the NEC so yes they are governed by the same code

Above drop ceiling space is often (most likely?) plenum which is possibly why the prohibition of NM in commercial.

This area of the code is not my forte but I am guessing above drop ceiling to be super safe you'd want to use plenum rated not just in wall for everything.

 

[alfredeneuman]

Read the very first post.

 

[cybrdyke]

Above drop ceiling space is often (most likely?) plenum which is possibly why the prohibition of NM in commercial.

This area of the code is not my forte but I am guessing above drop ceiling to be super safe you'd want to use plenum rated not just in wall for everything.

Correct. Everything in this area needs to be plenum rated, all the way down to the cable ties. No romex, pvc pipe or fittings, plastic boxes, etc....
CD

 

[Chukster]

Correct. Everything in this area needs to be plenum rated, all the way down to the cable ties. No romex, pvc pipe or fittings, plastic boxes, etc....
CD

Fortunately in my case, the volume above the celing planks will NOT be part of return plenum. But I've noted everyone's comments about why flexible cords are not allowed up there. Thanks.

On the other hand, I just looked at the SOC (state of construction) down there, with the HVAC guys doing stuff. This question is really for
non-electrical' section:

Some of the returns in the house are panned joists - I guess it was still allowable around '68? But of course, not very well. In general housing construction code, if the HVAC is being modified, do they have to correct the panned joists, and tighten up the system? As of right now, they are re-using some of those ducts, and passing supply ductwork thru the existing return.

Yes, THRU the existing return, and I have to infer that there is no cross-leakage.

It seems quite the cluster to me right now.

 

[n8n]

When I said it was often a plenum, I was referring to commercial, which is the world I work/live in. In residential, you have to assess whether it is or isn't. but in commercial, you can pretty much assume it is and be right 95% of the time.