Divya, Home Buyer in San Francisco, CA

What’s the difference between copper and plastic piping?

Asked by Divya, San Francisco, CA Mon May 21, 2012

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San Francisco hasn't allowed plastic pipes for water supply ever as far as I know. Probably earthquake issues are the reason. Copper is the newer material over the older galvanized pipes used when most homes in the city were plumbed. Galvanized pipes build up corrosion inside them which reduces the flow volume and adds rust particles to the water sometimes.
Copper throughout the entire house means that there will probably mean no major plumbing work to do. Also whenever remodeling is done copper is installed.
2 votes Thank Flag Link Mon May 21, 2012
Great answer Jed. Having seen some cracked or leaking galvanized pipes recently, copper is definitely the way to go!!!
Flag Mon May 21, 2012
Jed Lane; Fog…, Real Estate Pro in San Francisco, CA
One thing to keep in mind here is that galvanized metal should never come in direct contact with copper. This includes something as simple as some plumbers tape (made from Galvanized metal) touching copper piping (from the outside). I know that's hard to believe but the 2 metals touching causes electrolysis. Plastic or brass is neutral enough the use between both metals.

I know that's off topic from what you were originally asking about but I thought it is good to make a note of this just in case you ever run in to this while checking those pipes.
1 vote Thank Flag Link Wed May 23, 2012
Cross-linked polyethylene or PEX piping is considered by many to be superior to copper. About the only people that don't like it are the pipefitters unions because they can be installed much faster than copper and therefore the plumbers get paid less for the jobs. They do costs a bit more, but when the costs of labor is figured in they are a costs saver.
Web Reference: http://www.SacRELender.com
1 vote Thank Flag Link Mon May 21, 2012
Everything is a trade off between strengths and weaknesses:
top quality copper will last 50+ years if not subject to electrolysis, but it's more vulnerable to settlement and earthquake, exposes users to minute amounts of lead, and copper. PEX is hard and flexible, I don't know if history shows any problems from rodent attacks? Being a chemical based product, it exposes users to some amount of chemicals which many may prefer to avoid. PEX is faster to install, only approved for use in San Francisco about a year ago per my plumber source who uses it.
0 votes Thank Flag Link Mon Jun 24, 2013
PEX is now allowed in San Francisco. Sorry to double post on this, but I wanted to make sure the message didn't get lost.
0 votes Thank Flag Link Mon Jun 24, 2013
How long are you going to own the Property ??. Copper will probably outlast you.( Ya have children?) and it's rat proof, depending on you area. If your going to call it home, go copper. If your going to flip, take the cheaper way out, your call. But keep in mind, Buyers aren't that stupid and they do have eyes and hopefully a good Real Estate Agent.

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0 votes Thank Flag Link Fri Mar 22, 2013
Functionally, they're pretty much the same: in almost all municipalities in the U.S., plastic (PEX for water supply, ABS for waste) is allowed for supply and waste lines. Plastic has been allowed in Europe for a long time. Some early plastic piping had problems, but it seems as if the problems have been worked through, and plastic is now allowed nearly everywhere. Where it's allowed, it's used nearly universally, as the materials and labor are much less expensive than for copper.

For a variety of reasons, San Francisco code doesn't allow plastic: for supply, copper is required. I've seen two houses in San Francisco where someone saved a buck by hiring someone who didn't know the local codes, and all the plumbing had to be ripped out and done again. The domino effect of the fallout was severe, for the plumbers, generals, and homeowners. Just make sure your contractor knows the SF codes and has the plumbers who have real experience with copper.
0 votes Thank Flag Link Sun Jun 10, 2012
This situation has changed. San Francisco now allows PEX tubing.
Flag Mon Jun 24, 2013
Tania is right. In fact that also includes the type of brackets you use to hold the piping in place. I heard of a house in the bay area blowing up when the homeowner replaced the copper bracket with a galvanized one on the gas line in the subfloor. (They did probably save 50 cents because the copper ones do costs more though.) The electrolysis ate a pinhole in the copper pipe and the subfloor filled-up with gas; add a spark and kaboom!
Web Reference: http://www.SacRELender.com
0 votes Thank Flag Link Thu May 24, 2012
One brings the water in, the other takes it out.
0 votes Thank Flag Link Mon May 21, 2012
The difference can be huge depending on what purpose each type of pipe is being used for. Need more details.

Oggi Kashi
Broker Associate, Paragon Real Estate Group CA DRE 01844627
All data from sources deemed reliable but subject to errors and omissions, and not warranted. truonly
Web Reference: http://www.oggikashi.com
0 votes Thank Flag Link Mon May 21, 2012
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