When is PVC not allowed indoors?
- Thread starter cppoly
- Start date
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Probably because it's relatively flexible and fragile.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Its use might be restricted by the fire code. It makes some noxious smoke when it burns.
Or it might just be tradition or design choices. Especially in smaller sizes it does not hang as straight as metal and does not look as nice.
It also flexes more from thermal effects.
Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
I also think securing it horizontally and the bends make it harder to use than EMT.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I meant why we don't see it, not that it's an NEC issue.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Cuz PVC sucks as an indoor wiring method 
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I am sure it has to do with its toxicity indoors.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Many commercial spaces use return air plenums above hung ceilings so PVC cannot be used there.
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
Lots of states haven't allowed new systems like that to be installed. WA hasnt allowed that style of plenum in new work for 20 years or so. Same as using a joist bay as a plenum which has fallen out of favor and been removed as an option for many.
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
In California you can't use the building structure as a supply or return, it has to be a ducted system.
The California 2005 Building Energy Efficiency Standards (Title 24, Part 6). "Building spaces such as cavities between walls, support platforms for air handlers, and plenums defined or constructed with materials other than sealed sheet metal, duct board, or flexible duct must not be used for conveying conditioned air including return air and supply air. The practice of using drywall materials as the interior surface of a return plenum is not allowed".
The California 2005 Building Energy Efficiency Standards (Title 24, Part 6). "Building spaces such as cavities between walls, support platforms for air handlers, and plenums defined or constructed with materials other than sealed sheet metal, duct board, or flexible duct must not be used for conveying conditioned air including return air and supply air. The practice of using drywall materials as the interior surface of a return plenum is not allowed".
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
California wont fix broken intake duct, stepped on, or punctured, so legionnaires, asbestos, black mold, vermin feces, & smoldering toxins may still get occupants sick.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
I installed PVC in ug water flow meter vaults and in above ground chlorination rooms. It’s much slower to install than EMT, and while pre bent elbows can be used, they have a diy look.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
That’s why it’s not used so much in commercial. Looks like a hack or romex jockey jockey installed it. Along with it not looking good without a whole lot of strapping!
fishin' electrician
Senior Member
- Location
- Connecticut
Geez, don't look at that plumbing!
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
For what it's worth it's prohibited in a structure in San Francisco, too. Local ammendment. From what I've read NYC has more such rules than SF.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Thanks to @ron for posting this in another thread, regarding NYC specifically:
On pg 47 there's an ammendment to article 352 that prohibits PVC in any residential building or dwelling not exceeding three floors above grade.
On pg 47 there's an ammendment to article 352 that prohibits PVC in any residential building or dwelling not exceeding three floors above grade.
In NYC, looks like PVC is permitted in residential buildings above 3 stories or commercial buildings (of any height) within non-plenum walls, floors, and ceilings that have a one hour rated assembly. It looks like it's only prohibited in plenum spaces and OK everywhere else indoors (excluding the Uses Not Permitted section 352.12: hazardous locations, etc.).