emt conduit on rooftop

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rooftop PVC. it needs to be protected from sunlight. since most paints will fall off over time, if it will be exposed to sunlight everyday then i myself would not use PVC. there are wraps that can be used (pita). you also need proper expansion joints if needed.
 
FionaZuppa said:
rooftop PVC. it needs to be protected from sunlight. since most paints will fall off over time, if it will be exposed to sunlight everyday then i myself would not use PVC. there are wraps that can be used (pita). you also need proper expansion joints if needed.
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It is required to be sunlight resistant.
 
FionaZuppa said:
rooftop PVC. it needs to be protected from sunlight. since most paints will fall off over time, if it will be exposed to sunlight everyday then i myself would not use PVC. there are wraps that can be used (pita). you also need proper expansion joints if needed.
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You clearly have zero experience in the electrical trade and should not be commenting on wiring and installation practice.
 
iwire said:
It is required to be sunlight resistant.
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i am very familiar with PVC compounds, it will all (gray, white, blue, black, pink, red, whatever) degrade when exposed to UV, makes for a poor choice when exposed to sunlight.

the industry is slowly but surely moving to HDPE. in the near future NEC will have to add "HDPE" as a conduit material type.


peter d said:
You clearly have zero experience in the electrical trade and should not be commenting on wiring and installation practice.
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for the purposes of curiosity, i will entertain your rhetoric here. care to enlighten us?
 
FionaZuppa said:
i am very familiar with PVC compounds, it will all (gray, white, blue, black, pink, red, whatever) degrade when exposed to UV, makes for a poor choice when exposed to sunlight.
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I don't know much about PVC but so far the NEC disagrees with you.
 
infinity said:
I don't know much about PVC but so far the NEC disagrees with you.
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no, they dont disagree with me, "electrical PVC", otherwise known as PVC with UV stabilizers in it, is the best plastic for the job currently. HDPE will eventually take over. [FONT=&quot]UL651 is ok but it doesnt really give us the full story. PVC will become very brittle. check with some of the electrical contractors in FL,TX,AZ and see what they say about PVC on rooftop. it becomes very brittle over time and ease of cracking becomes an issue due to a slight bump. if its PVC many will coat it with a coating to extend its life. the question was PVC or metal, i would use metal on rooftop.[/FONT]
 
FionaZuppa said:
no, they dont disagree with me, "electrical PVC", otherwise known as PVC with UV stabilizers in it, is the best plastic for the job currently. HDPE will eventually take over. [FONT=&quot]UL651 is ok but it doesnt really give us the full story. PVC will become very brittle. check with some of the electrical contractors in FL,TX,AZ and see what they say about PVC on rooftop. it becomes very brittle over time and ease of cracking becomes an issue due to a slight bump. if its PVC many will coat it with a coating to extend its life. the question was PVC or metal, i would use metal on rooftop.[/FONT]
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Reality proves your worries to be false.
 
FionaZuppa said:
i am very familiar with PVC compounds, it will all (gray, white, blue, black, pink, red, whatever) degrade when exposed to UV, makes for a poor choice when exposed to sunlight.

the industry is slowly but surely moving to HDPE. in the near future NEC will have to add "HDPE" as a conduit material type.



for the purposes of curiosity, i will entertain your rhetoric here. care to enlighten us?
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Yes, based on this posting below it is very apparent you don't understand wiring methods and what is and is not allowed by the NEC.

FionaZuppa said:
no, they dont disagree with me, "electrical PVC", otherwise known as PVC with UV stabilizers in it, is the best plastic for the job currently. HDPE will eventually take over. UL651 is ok but it doesnt really give us the full story. PVC will become very brittle. check with some of the electrical contractors in FL,TX,AZ and see what they say about PVC on rooftop. it becomes very brittle over time and ease of cracking becomes an issue due to a slight bump. if its PVC many will coat it with a coating to extend its life. the question was PVC or metal, i would use metal on rooftop.
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Therefore I disregard anything you have to say on this subject.
 
FionaZuppa said:
i am very familiar with PVC compounds, it will all (gray, white, blue, black, pink, red, whatever) degrade when exposed to UV, makes for a poor choice when exposed to sunlight.

the industry is slowly but surely moving to HDPE. in the near future NEC will have to add "HDPE" as a conduit material type.?
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It is great watching you comment on the NEC when clearly you have not looked in one. The NEC has had a HDPE article for a while. But it can't be used for the OPs project.

353 High Density Polyethylene Conduit: Type HDPE Conduit
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353.12 Uses Not Permitted. HDPE conduit shall not be used under the following conditions:

(1) Where exposed
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for the purposes of curiosity, i will entertain your rhetoric here. care to enlighten us
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He means you have no hands on experiance installing or maintaining PVC installtions outside so your opinions here carry no weight.
 
peter d said:
Yes, based on this posting below it is very apparent you don't understand wiring methods and what is and is not allowed by the NEC.
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you have a hard time of understanding. i never said PVC could not be used, i said my choice would be metal.
 
FionaZuppa said:
it needs to be protected from sunlight.
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My utility (a small one, Duke Energy) uses it on their poles (right in my backyard) to carry medium voltage from the top of the pole to my neighborhood's pad mount transformers. You'd think they would need to know of your issues.

FionaZuppa said:
You also need proper expansion joints if needed.
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That is true. Doesn't it also apply to other rigid conduit systems, of course their thermal expansion is muck less so less often a problem?
 
FionaZuppa said:
you have a hard time of understanding. i never said PVC could not be used, i said my choice would be metal.
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And you tried to substantiate that claim by saying that PVC would get brittle and break with the slightest bump. Of course it will get brittle over time and break if something were to hit it. But EMT and even RMC degrade over time as well.
 
peter d said:
And you tried to substantiate that claim by saying that PVC would get brittle and break with the slightest bump. Of course it will get brittle over time and break if something were to hit it. But EMT and even RMC degrade over time as well.
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true. in AZ where avg humidty is ~35% and rain happens a few x a year, metal is better. in FL, salt water is a nightmare for metals, PVC is better choice. OP is on LI, humidity is rather hi there for most of the year and UV from sun is not so much (too cloudy most days), so maybe PVC is better.

i guess you missed my point, if UV is killer, use metal, if moisture is hi, use PVC. i guess s FL you have to pick, but if HDPE was available i would use HDPE over metal in s FL.
 
FionaZuppa said:
i guess you missed my point, if UV is killer, use metal, if moisture is hi, use PVC. i guess s FL you have to pick, but if HDPE was available i would use HDPE over metal in s FL.
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And I guess you cannot read my post above.

It is a violtion to use HDPE expossed.
 
FionaZuppa said:
true. in AZ where avg humidty is ~35% and rain happens a few x a year, metal is better. in FL, salt water is a nightmare for metals, PVC is better choice. OP is on LI, humidity is rather hi there for most of the year and UV from sun is not so much (too cloudy most days), so maybe PVC is better.

i guess you missed my point, if UV is killer, use metal, if moisture is hi, use PVC. i guess s FL you have to pick, but if HDPE was available i would use HDPE over metal in s FL.
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I live in New England, the climate is exactly the same as Long Island and that's why I would not use EMT. It degrades and rusts very rapidly here.
 
peter d said:
I live in New England, the climate is exactly the same as Long Island and that's why I would not use EMT. It degrades and rusts very rapidly here.
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well, perhaps you chose the wrong type of metal :thumbsup:

iwire said:
And I guess you cannot read my post above.

It is a violtion to use HDPE expossed.
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art 353, what about it??
HDPE will eventually surpass what PVC can do in all regards. HDPE is also more environmentally better to make than PVC.

for the OP, perhaps run PVC and be done with it. if you want to add a little extra PVC protection, spray the top with gray acrylic spray or a clear acrylic primer spray. this adds some additional UV protection, but certainly not a requirement.
 
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