Is it a NEC code violation to paint PVC

The_Archer

Member
Location
New York
I know it is prudent to confirm everything with JHA, however does painting PVC violate 110.3 (B) Installation and Use, or 110.21(A) Marking: Manufacturers Marking as referenced in 352.120 Marking? The conduit is not going underground. The example would be running PVC exterior on a roof associated with a Photovoltaic system. I guess I am answering my own question but I suppose PVC can be painted if the manufacturers mark can still be observed....?
 

jumper

Senior Member
I know of know rule that says you cannot paint, assuming the "paint" is non corrosive, conduit or that the manufactures info on the raceway must be be exposed for inspection for general installs.
 

jumper

Senior Member
I know of know rule that says you cannot paint, assuming the "paint" is non corrosive, conduit or that the manufactures info on the raceway must be be exposed for inspection for general installs.

Oops. Need to look before I leap.:ashamed1:

Still does not say you cannot paint it after it is installed and inspected.

352.120 Marking.
Each length of PVC conduit shall be
clearly and durably marked at least every 3 m (10 ft) as
required in the first sentence of 110.21(A). The type of
material shall also be included in the marking unless it is
visually identifiable. For conduit recognized for use above-
ground, these markings shall be permanent. For conduit
limited to underground use only, these markings shall be
sufficiently durable to remain legible until the material is
installed. Conduit shall be permitted to be surface marked
to indicate special characteristics of the material.
 

The_Archer

Member
Location
New York
I know of know rule that says you cannot paint, assuming the "paint" is non corrosive, conduit or that the manufactures info on the raceway must be be exposed for inspection for general installs.

Yeah, that is what I have been doing. I would like to do it before inspection. I am wondering if I can face the manufacturers labeling face down and paint the rest of the conduit and leave the writing exposed, or paint the conduit with writing face down on roof and then scratch off one area to show the manufacturers specs. Thanks for the input.
 

jumper

Senior Member
Yeah, that is what I have been doing. I would like to do it before inspection. I am wondering if I can face the manufacturers labeling face down and paint the rest of the conduit and leave the writing exposed, or paint the conduit with writing face down on roof and then scratch off one area to show the manufacturers specs. Thanks for the input.

Unless it an area that required schedule 80 vs. 40, I am guessing this is not, why would an average inspector care?

I would just show my purchase order if he thinks I was using something other than listed conduit.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
JMO. The code requires certain markings on the conduit (as it does for other raceways such as EMT). It does not say these markings have to be visible after the install is done. The inspector may wish to see the markings prior to them being painted.
 

macmikeman

Senior Member
Any inspector who insists on unpainted pvc is pushing the limits on overbearing and needs a new job. How many of you guys here go around manufacturing your own pvc in your basement.......... Seriously. He needs a new job. A dolt.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Any inspector who insists on unpainted pvc is pushing the limits on overbearing and needs a new job. How many of you guys here go around manufacturing your own pvc in your basement.......... Seriously. He needs a new job. A dolt.

I suppose there is some potential that someone might use water pipe instead of conduit. i can't imagine how it would matter much though if someone did.
 

Carultch

Senior Member
Location
Massachusetts
I suppose there is some potential that someone might use water pipe instead of conduit. i can't imagine how it would matter much though if someone did.

If that's the case, the best strategy to prove that you used listed electrical PVC is to take a photo of the print legend on the installed conduit, before you apply the paint.
 

Carultch

Senior Member
Location
Massachusetts
I know it is prudent to confirm everything with JHA, however does painting PVC violate 110.3 (B) Installation and Use, or 110.21(A) Marking: Manufacturers Marking as referenced in 352.120 Marking? The conduit is not going underground. The example would be running PVC exterior on a roof associated with a Photovoltaic system. I guess I am answering my own question but I suppose PVC can be painted if the manufacturers mark can still be observed....?

In my opinion, running PVC on a rooftop, exposed to direct sunlight, is asking for trouble. That conduit is going to expand and contract like crazy, and in spite of its "sunlight resistant" rating, it will degrade during the service life of the system. It will never look as good as the drawing you installed it from, after several years. Plus, there is the potential for physical damage of foot traffic on the rooftop, and if you run RMC or IMC, it will be much better at withstanding this.

You will also need more supports for PVC than RMC/IMC as well.
 

JFletcher

Senior Member
Location
Williamsburg, VA
JMO. The code requires certain markings on the conduit (as it does for other raceways such as EMT). It does not say these markings have to be visible after the install is done. The inspector may wish to see the markings prior to them being painted.

as is evidenced by every grocery and bb store having painted ceilings, emt, sprinkler pipe, everything up there is painted
 

iwire

Moderator
Staff member
Location
Massachusetts
JMO. The code requires certain markings on the conduit (as it does for other raceways such as EMT). It does not say these markings have to be visible after the install is done. The inspector may wish to see the markings prior to them being painted.

Exactly.
 

kwired

Electron manager
Location
NE Nebraska
Even if not painted, not all markings will be visible after installation. Some may be facing the wall, some short pieces may be cut from sections that don't have any marking. Those markings sometimes do fade in sunlight also.
 

pv_n00b

Senior Member
Location
CA, USA
In my opinion, running PVC on a rooftop, exposed to direct sunlight, is asking for trouble. That conduit is going to expand and contract like crazy, and in spite of its "sunlight resistant" rating, it will degrade during the service life of the system. It will never look as good as the drawing you installed it from, after several years. Plus, there is the potential for physical damage of foot traffic on the rooftop, and if you run RMC or IMC, it will be much better at withstanding this.

You will also need more supports for PVC than RMC/IMC as well.

Interesting, I've never seen RMC or IMC on a roof. It would be overkill to run heavy pipe unless maybe you were worried about a meteor strike. :blink: The choice is usually between PVC and EMT. I've heard arguments for and against PVC on the roof, but it's used a lot in Hawaii and on the coasts due to the corrosive environment. While I have heard a lot of people warn about using it I have not seen any cases where it has failed if it was installed properly. The only problem I have actually seen is that in a fire PVC melts and exposes conductors where EMT does not.
 

kwired

Electron manager
Location
NE Nebraska
Interesting, I've never seen RMC or IMC on a roof. It would be overkill to run heavy pipe unless maybe you were worried about a meteor strike. :blink:
Meteor strike may damage the RMC as well. Some places have frequent severe thunderstorms with damaging hail being likely at least once or twice every 5-10 years.
 

iwire

Moderator
Staff member
Location
Massachusetts
Interesting, I've never seen RMC or IMC on a roof. It would be overkill to run heavy pipe unless maybe you were worried about a meteor strike.

RMC is a common job specification for roof conduits that we run.

The choice is usually between PVC and EMT. I've heard arguments for and against PVC on the roof, but it's used a lot in Hawaii and on the coasts due to the corrosive environment.

We use RMC, EMT or PVC on roofs dependent on the job.


While I have heard a lot of people warn about using it I have not seen any cases where it has failed if it was installed properly. The only problem I have actually seen is that in a fire PVC melts and exposes conductors where EMT does not.

In this area I often find EMT rusted away completely in sections with just the conductors remaining. Maybe its the fact they end up buried in snow many times.
 

Carultch

Senior Member
Location
Massachusetts
Interesting, I've never seen RMC or IMC on a roof. It would be overkill to run heavy pipe unless maybe you were worried about a meteor strike. :blink: The choice is usually between PVC and EMT. I've heard arguments for and against PVC on the roof, but it's used a lot in Hawaii and on the coasts due to the corrosive environment. While I have heard a lot of people warn about using it I have not seen any cases where it has failed if it was installed properly. The only problem I have actually seen is that in a fire PVC melts and exposes conductors where EMT does not.

All I know is that whenever it has been up to my company, EMT and PVC are not to be installed where exposed on a rooftop in direct sunlight. Occasionally small segments of PVC are acceptable in the shade of the modules, but not as your main conduit system on the rooftop.

I have seen examples where the PVC conduit system turns into a complete pretzel from poor management of thermal expansion or improper support.

As for EMT, it probably has to do with the corrosion esistant coating not being as thick as it is for RMC/IMC, and/or the fact that the compression fittings aren't as robust as the threaded counterparts. It could also be that in heavy snowfall and foot traffic, the location is subject to physical damage. Not that there is any objective standard for what is and isn't subject to physical damage.
 
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