To PVC or not to PVC...

[Plumguy]

Around here all water mains are either poly or copper (soft roll), I've never seen a water main installed with joints on it except the old galvy lines and usually when they leaked it was at a coupling. I have dug a few front yards to make the repair. Even sprinkler systems are done in poly and if the system is an afterthought they install the poly with a ditchwitch.

Backfilling pipes around here is taken pretty serious and if the pipes are not in a bed of beach like sand with at least 3" around it you won't get it approved and would certainly be liable for the pipe!

 

[Andrew P.]

PVC works fine

I need to replace my main water line (from meter to house) ... should I use PVC or copper for the main supply line? Or maybe I should ask it another way... I would like to use PVC, is there a reason I shouldn't?

The bottom line is that you should check to see if local plumbing codes have restrictions on use of PVC for domestic potable water; as far as I know, most don't, but there may be restrictions on use of PVC within the foundation boundary, as is the case in my local jurisdiction, where only galvanized iron, copper, CPVC and PEX are permitted inside the building.

I had my sewer lateral replaced in June 2001 by a pipeline contractor, during which I also discovered that the galvanized iron main water line from the meter at the curb was shot, so they replaced it with 1-inch PVC for no additional charge. The job was done under a building permit. The city building inspector saw the PVC pipe before the second trench was covered and signed it off without comment. It's been working flawlessly for 10 years, and I don't have to worry about rust flecks or leaks anymore. I'm happy. My house was built in the late 1950s. There are tract houses in my neighborhood that were built in the late 1970s where white PVC pipe was used underground for the main supply from the meter to the house and galvanized iron was used for the interior plumbing.

The only drawback I can see with PVC is that the white variety typically used for drinking water is slightly translucent and if water is allowed to stagnate in a section that is above ground, there's a likelihood of algae growing inside the pipe. I've seen this happen where PVC was used in irrigation systems. In my opinion, PVC is fine as long as it is buried or used in a dark crawlspace or basement. If any section needs to be exposed to daylight, I'd use gray PVC for such areas — normally used as electrical conduit — as it is completely opaque. In the alternative, cover it with an opaque pipe wrap of some sort.

 

[Sponsor]

 

[Andrew P.]

#1. I have been in this business for over 55 years so I have installed a lot of copper and PVC water lines to houses. I have never installed a poly, ...

"Poly" isn't any type of plastic. It's a Greek prefix that means "many". It can be the start of polystyrene, polyethylene, polypropylene, polybutylene, polymorphism, polygamy, etc. ad infinitum.