Damp location recessed lights

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goldstar

goldstar

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Location
New Jersey
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Electrical Contractor
I was asked by a GC to provide a quote for 8 recessed lights that are going under an outdoor deck. The decking will have a rubber membrane laying across the top of the joists before the decking goes down so I can use new work cans below. Once the cans are installed there will be a ceiling installed (probably some form of decking as well). They also want to install 2 paddle fans under this deck. So, here are my questions :
  1. Does anyone know of a recessed light fixture that I can use for this application ? I don't know that the area between the joists is going to be excessively wet but I'm guessing it may be damp. Deck will be pitched away from the house to allow water run-off.
  2. What would you use as a wiring method ? I'm thinking UF cable and the appropriate UF connectors
  3. What would you use to support the fan ? I'm thinking a regular fan brace & JB. HO is buying the fans

Thanks in advance for your opinions.
 
IMO, the area is damp not wet, hence the membrane so regular cans should work. I know that Halo cans are damp rated and I am guessing they all are.

I would use nm cable because I don't consider between the joists as damp location. If it were then attic spaces would be also.

I standard fan brace works but the fan must be damp location rated
 
Dennis Alwon said:
IMO, the area is damp not wet, hence the membrane so regular cans should work. I know that Halo cans are damp rated and I am guessing they all are.

I would use nm cable because I don't consider between the joists as damp location. If it were then attic spaces would be also.

I standard fan brace works but the fan must be damp location rated
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i would say no, NM is not allowed in this install. the decking, covered or not underneath, will be subject to uncontrolled dampness/moisture. a attic is designed to vent properly. if attics were damp you would have major mold issues.
i might call the install "damp". depending on the zone its in the AHJ may consider such a wet location. fan boxes will likely be WP.
my advice would be to call AHJ and ask what they think of it.

Location, Damp. Locations protected from weather and
not subject to saturation with water or other liquids but
subject to moderate degrees of moisture.

Location, Wet. Installations underground or in concrete
slabs or masonry in direct contact with the earth; in locations
subject to saturation with water or other liquids, such
as vehicle washing areas; and in unprotected locations exposed
to weather.
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FionaZuppa said:
i would say no, NM is not allowed in this install.
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I disagree w/this, and do agree w/ Alwon- the area between the joists sure doesn't sound like a damp loc, b/c of this........


goldstar said:
The decking will have a rubber membrane laying across the top of the joists before the decking goes down..........
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Would you agree that nm in an unvented ext wall is a damp location? I do agree that ahj has the final say, but imo, if they are ok w/nm, that's what the op should use- he's within code and there is no hazard.
 
goldstar said:
I was asked by a GC to provide a quote for 8 recessed lights that are going under an outdoor deck. The decking will have a rubber membrane laying across the top of the joists before the decking goes down so I can use new work cans below. Once the cans are installed there will be a ceiling installed (probably some form of decking as well). They also want to install 2 paddle fans under this deck. So, here are my questions :
  1. Does anyone know of a recessed light fixture that I can use for this application ? I don't know that the area between the joists is going to be excessively wet but I'm guessing it may be damp. Deck will be pitched away from the house to allow water run-off.
  2. What would you use as a wiring method ? I'm thinking UF cable and the appropriate UF connectors
  3. What would you use to support the fan ? I'm thinking a regular fan brace & JB. HO is buying the fans

Thanks in advance for your opinions.
Click to expand...
Have done this on more than one home, used regular halo cans and romex and like Dennis said make sure the fan is outdoor rated or the blades turn into noodles.
 
IMO I would treat this application in the same way I would an attached porch with a roof.

Halo and LOL should be fine to use and so would NM between the ceiling and the deck.
 
i would be interested in hearing what the AHJ says. i am willing to bet that AHJ will call it damp location and thus NM not allowed there.


an exposed deck with cans & wiring underneath, even with membrane up above, is in no way the same as a porch ceiling. the upper part of the deck, is it used for people traffic or is it a "flat roof"?
 
FionaZuppa said:
i would be interested in hearing what the AHJ says. i am willing to bet that AHJ will call it damp location and thus NM not allowed there.


an exposed deck with cans & wiring underneath, even with membrane up above, is in no way the same as a porch ceiling. the upper part of the deck, is it used for people traffic or is it a "flat roof"?
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I have done this many times and never had an issue with nm - same as the others. There is probably more moisture in many crawl spaces then there is in that space. If there was that much moisture then it would leak all over the place. The membrane is installed to drain away from the building.Would you not accept nm cable in a porch roof? Not much difference especially if the roof were a flat roof.
 
Dennis Alwon said:
I have done this many times and never had an issue with nm - same as the others. There is probably more moisture in many crawl spaces then there is in that space. If there was that much moisture then it would leak all over the place. The membrane is installed to drain away from the building.Would you not accept nm cable in a porch roof? Not much difference especially if the roof were a flat roof.
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so what you would essentially have is a decking installed over a roofing system. a membrane alone is not meant for constant foot traffic. if the structure was built a certain way then i will agree with you, but as described i bet ya the AHJ will mark it as damp (possibly wet) location. i may be wrong, thus why i said i would like to know what the AHJ says.

and to be honest, a bid like this comes up and its questionable, dont come here, ask the AHJ, saves time and headache. we all might say "passes inspection where i am", then he goes and does a NM install with wrong fixtures only to have AHJ tell him "nope, sorry".

the nec doesnt tell us exactly what damp and wet locations are per locale, thats up to the AHJ. its the whole reason why plans are submitted to AHJ for permitting, and if AHJ sees that the plans dont show damp or wet location when it should be marked as such the AHJ will make you adjust before issuing permit.

not permitting or dont care to know the opinion of the AHJ? ok, then wire with THHN w/ staples w/o conduit, doesnt really matter at that point.
 
FionaZuppa said:
but as described i bet ya the AHJ will mark it as damp (possibly wet) location. i may be wrong, thus why i said i would like to know what the AHJ says.
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You are wrong.

There are a number of us who deal with AHJs all the time telling you that the AHJs we deal with will accept this.

There are many locations that are damp that NM has been and is allowed in. As Dennis points out, crawl spaces, car ports, etc

It would be a major change if AHJs suddenly started pushing the damp location issue.
 
FionaZuppa said:
so what you would essentially have is a decking installed over a roofing system. a membrane alone is not meant for constant foot traffic. if the structure was built a certain way then i will agree with you, but as described i bet ya the AHJ will mark it as damp (possibly wet) location. i may be wrong, thus why i said i would like to know what the AHJ says.
Click to expand...

You are right and the membrane will not be rated for constant foot traffic. I have never seen one of these where the membrane was exposed. I would think there will be tile or some other floor covering.

I don't really get into how the deck is built but if it leaks that's some else's problem. The AHJ should approve this installation. I don't worry about a bathroom that may leak on the floor below either.
 
iwire said:
You are wrong.

There are a number of us who deal with AHJs all the time telling you that the AHJs we deal with will accept this.

There are many locations that are damp that NM has been and is allowed in. As Dennis points out, crawl spaces, car ports, etc

It would be a major change if AHJs suddenly started pushing the damp location issue.
Click to expand...

I agree with Dennis and the Yankee. It would pass here and VA no problem.
 
growler said:
You are right and the membrane will not be rated for constant foot traffic. I have never seen one of these where the membrane was exposed. I would think there will be tile or some other floor covering.
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The membrane is not subject to damage.

First joists go in, then membrane, then the deck boards go down over the membrane.
 
iwire said:
The membrane is not subject to damage.

First joists go in, then membrane, then the deck boards go down over the membrane.
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so you basically puncture the membrane when attaching the boards?

me still would like to know what AHJ says for this specific install.
 
FionaZuppa said:
so you basically puncture the membrane when attaching the boards?

me still would like to know what AHJ says for this specific install.
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That is like saying you puncture a metal roof when you fasten it down. Nope that is dealt with also

BTW, I have seen these installs where there is an actual metal pan in the joist space that have a slight grade away to the outside just in case any water gets in. I have never seen an issue with it.

Seriously if you are really worried about nm cable in a damp location then you should worry more about the rolls we see everyday in the back of peoples pickups. Inside the van is dry but would you consider that damp location? All that wire sitting there for weeks at a time. It really is not an issue

Honestly, I am not saying to do this by any means but I have seen NM cable buried in the ground and it had been there over 20 years without an issue. I am not talking about inside conduit either-- directly in the ground
 
Not sure exactly when this job is going to take place but I would imagine sometime soon. I will post photos as I know more about the job and see how the decking goes down. As far as I know to date both Dennis and Iwire are correct in the installation of the decking. If I find out otherwise I will post it. Thank you all
 
FionaZuppa said:
so you basically puncture the membrane when attaching the boards?

me still would like to know what AHJ says for this specific install.
Click to expand...

This is how I have seen it done. I am no building expert so I am sure I will be leaving out many details.
Typically what happens in an application like this is that after the membrane is installed the GC may use "sleepers" they maybe2x4's or larger. the joists are placed on top the EPDM without penetrating it (basically floating). The rest of the decking is secured the main structure in a way that should pass a building inspection.
 
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