out here in crazy California we are starting to see more and more houses plumbed with the plastic "Pex" tubing. It makes bonding the water system a little difficult. We have been bonding the 6" copper stub out where the water main comes into the house. I was just curious what other peoples thoughts and comments are on the subject. The inspectors around here don't really have much to say about it.
Don't confuse the requirement to bond the Grounding Electrode (250.50)and the requirement to bond the metal water pipe(250.104). 250.50 requires you to bond that 6" metal stub from outside, but if there aren't any metal water pipes inside, then 250.104 is moot.
#74193 - 01/16/0707:00 PMRe: Water Bond on Pex plumbed houses.
PEX is making inroads here, but traditional copper pipe is still the norm for internal plumbing in most houses.
However, plumbers are increasingly using plastic push-fit couplings instead of either soldered joints or brass compression fittings, which means that in many cases we have to go around with pipe clamps and short lengths of bonding cable to jumper across the joins.
#74194 - 01/16/0708:03 PMRe: Water Bond on Pex plumbed houses.
We had the same issue at a concrete tilt-up business park we did from the ground up. The copper plumbing exited the wall outside each suite, and became 2" pvc before it hit the dirt. Solution? Ufer grounds. But it was still quite silly to have to put ground clamps on the copper pipes which really went nowhere, just for show & inspection.
#74196 - 01/17/0701:32 PMRe: Water Bond on Pex plumbed houses.
If your copper water pipe is less than 10 feet, then it does not qualify as a grounding electrode, and does not need to be bonded. Regardless, supplemental ground rods need to be installed. I understand the origional reason for requiring supplemental ground rods when the only GE on the job is a metal water pipe is this scenario you have just described. One cannot rely upon the metal water pipe to be in contact with the earth for 10 feet, nor can it be relied on to stay metal.
#74197 - 01/17/0704:30 PMRe: Water Bond on Pex plumbed houses.
PEX is the greatest stuff ever- it's so cheap and so easy (especially considering copper prices now! $30 for 5' of 3/4" thin-wall cu pipe?) that it won't be long before it's used exclusively. We'd best just get used to it- if the GCs think about it, the foundation rebar would be a perfect electrode in place of the pipes.
#74199 - 01/18/0702:06 PMRe: Water Bond on Pex plumbed houses.
I haven't seen any copper in Florida new construction in 20 years. Cape Coral's lawsuits over pinholed copper was the death knell to anyone who might have wanted to do it. CPVC is the norm but some use PEX on a Maniblock system. My wife's half million dollar homes (and up) are CPVC. They don't bond anything except the pool but this year Florida is requiring the steel studs get bonded. A metal box somewhere in each wall section will suffice.