Schedule 80 flat roof

[cybersurge]

I am running single phase 220 #3 via schedule 80. Can I go over AC ducts fasting with uni to the flat roof or do I have to go under AC ducts? If under what would be the code that references that.

 

[coop3339]

PVC on a roof is not really a great plan so I would put it in the shade as much as possible if you have to use it

 

[petersonra]

Emt probably a better option.

 

[cybersurge]

PVC on a roof is not really a great plan so I would put it in the shade as much as possible if you have to use it

Thanks for that. Is it code to run schedule 80 on a flat roof that is always exposed to the sun. Also, is it code to run 2" schedule 80 over a AC don't if I fasten it to the roof with 18" high unistrut fastened to the roof?

 

[Fred B]

Expansion of PVC is substantial on a rooftop. Would go with EMT or Rigid if you have the option.

 

[Fred B]

Thanks for that. Is it code to run schedule 80 on a flat roof that is always exposed to the sun. Also, is it code to run 2" schedule 80 over a AC don't if I fasten it to the roof with 18" high unistrut fastened to the roof?

Check 352.44 for expansion rate. Suspended above a roof you will get a lot of sagging. Also 352.12(D) Ambient Temperatures. Where subject to ambient temperatures in excess of 50°C (122°F) unless listed otherwise. You could easily exceed that on a roof top. Have melted the bottoms of my boots on a roof.