# water bonding with pex



## Code05 (May 24, 2009)

You do not bond plastic water lines.


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## J. V. (Jun 1, 2007)

Hey OP. I am thinking about replacing my water line from the street to the house. Someone told me this PEX was the best way to go. I like the idea of zero couplings. It will be a straight run all the way from meter to inside of basement. What are you paying per foot? I will need about 250' at 3/4". Thanks John

Ps.....You do not bond plastic water lines. Just bond to the ground rods and or UFER.


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## 220/221 (Oct 9, 2007)

> How do you bond your ground when the house uses pex or plastic water supply?


Here, we haven't allowed the use of water piping as a ground for decades. It's ground rods or ufer if new construction.

Bonding is another issue. Lately, lots of existing interior piping systems, both water and gas, are getting broken up during remodel because so many plumbers are using non metallic pipe these days.

I believe the code says that the metallic pipe shall be bonded "where exposed" or something like that which is *very* open to interpetation since the short copper stubs on a pex system are exposed as well as the water heater stubs.


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## Termite (Apr 13, 2008)

Bonding and grounding aren't the same. A water service pipe must be used as a grounding electrode conductor _when available_...That's grounding. If it is pex, it isn't an acceptable grounding electrode conductor so you don't have to use it as a ground. The grounding system gives lightning a path to ground. 

Bonding metallic gas and water piping systems within the home is required. This is where it probably gets a little interpretive. Even with a pex service line, a house that is piped in copper should probably be bonded (not grounded). If it were to somehow become energized there's no way for the fault to clear a breaker since it isn't bonded to the grounding system.


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## nap (Dec 4, 2007)

220/221 said:


> Here, we haven't allowed the use of water piping as a ground for decades. It's ground rods or ufer if new construction.
> .



haven't allowed it? It is required by the NEC.


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## Termite (Apr 13, 2008)

nap said:


> haven't allowed it? It is required by the NEC.


Yup. :yes: Gotta have it when the water service is metallic.


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## nap (Dec 4, 2007)

thekctermite said:


> Bonding metallic gas and water piping systems within the home is required. This is where it probably gets a little interpretive. Even with a pex service line, a house that is piped in copper should probably be bonded (not grounded). If it were to somehow become energized there's no way for the fault to clear a breaker since it isn't bonded to the grounding system.


I believe code states all metallic <objects?> that may become energized must be bonded.250.4 A 4

that typically includes metal siding, steel duct work, and metal water pipe.

the fact is, it must be bonded to a GE system so it is also being grounded as well.


to the gas pipe; do you have a citation for that requirement? If I remember correctly, the code states that the EGC of the circuit that supplies the appliance that uses the gas is acceptable as the bonding/grounding of the gas piping. I just can't find it anymore.


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## Termite (Apr 13, 2008)

nap said:


> to the gas pipe; do you have a citation for that requirement? If I remember correctly, the code states that the EGC of the circuit that supplies the appliance that uses the gas is acceptable as the bonding/grounding of the gas piping. I just can't find it anymore.


Very true if the gasline hits a furnace. I've always thought that way as well, and the code agrees. However, if there's just a gas water heater or just a fireplace (etc) you have to bond it. The inspector would have discretion as to whether or not the gasline is capable of becoming energized.

*2003 IRC section E3509.7 Bonding to other metal piping:*
_*Where installed in or attached to a building or structure, metal piping systems, including gas piping, capable of becoming energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to one or more grounding electrodes used. The bonding jumper shall be sized in accordance with table E3808.12 using the rating of the circuit capable of energizing the piping. The equipment grounding conductor for the circuit that is capable of energizing the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.*_

Sorry, don't have an NEC at the house. The I-codes pretty much cite the NEC verbatim in most cases though.

The code makes it very clear that a metal gas pipe _cannot_ serve as a grounding electrode like a metal water line must.


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## AllanJ (Nov 24, 2007)

Two situations:

1. You are bonding the electrical system to the plumbing system because the main water line exiting the house is the grounding electrode,

2. You are bonding the plumbing system to the electrical system, the latter having a rod or other plumbing as the grounding electrode.

"Gas plumbing is never situation #1."

For a plastic main water line exiting the house or detached garage, situation #1 cannot apply.

It is possible to bond "isolated" metal portions of the plumbing system separated by plastic components by running ground wires more or less following the route of the plumbing through the house. As stated above, you can connect the ground wire for the isolated metal plumbing to the ground wire of certain nearby circuits* rather than run it all the way to the basement.

* A circuit that would be the cause if the person touching the plumbing in question were to be in danger of electrocution.


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## TROTZINKA (Apr 24, 2016)

I am only a General. But I Believe that when you use have pex as in interior pipeing ( water supply you have the following option's: 1. 1st run your ground wire to the ground rod, then you are bonding it at the water line main, if it is in metal. 2. if, your main water supply is other then metal ( plastic or pex ) then you install 2 ground rods, not more then 6 feet apart, then look it to your gas metal pipe for that bond. Note: the water pipe & gas pipe are bond's, not grounds. Also note, that if the water pipes are metal, the you should be bonding the hot & cold water at water heater prior to the flex connection to the water heater. This is California, it may be different in another state, where the NEC / UBC is not used. I further suggest, that in todays world of electronic's & cable, you supply a separate ground wire to the ground rod to a Ground bar/ lug type location where the Cable & Internet providers can connect. this stops any feed back from the panel, by isolating the ground and you getting any potential feed back from the electrical service. ( i..e. Transformer goes bad, that ground w/ the utility goes to your house ground and has the potential of feeding back into your electronics', which will damage the unit ) But, I am only a general, so ask your local building dept. as to what they require is the best, as Pex is still not a standard.


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## brric (Mar 5, 2010)

If you try real hard you may be able to find an older thread to reopen. Ground rods must be at least 6' apart.


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## Jim Port (Sep 21, 2007)

Thank you, I have been waiting almost 7 years a for that information .


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## TROTZINKA (Apr 24, 2016)

brric said:


> if you try real hard you may be able to find an older thread to reopen. Ground rods must be at least 6' apart.


You are absolutly correct, typo, min distance is 6 feet for locations where water lines can not be used as a bond. Since you are in the know. Here is another question which I am not sure of.
Bonnding to the gas line, where the supply to the gas meter's are now in plastic, in fact all the gas utility company's now run all their main lines in plastic to the meter. Is that bond still required or even relavent ? I have been doing it, just out of habit & and without question. But I truely wonder if it has been address in the code. My understanding, these bonds, basicly rely on going back to earth via the main line service supplied by the utility, weather water or gas. And thank you for correcting my screw up, 6 feet min is correct. And possibly you could address the question on the gas bond.
The reason for the reply to this older post was I was searching for a code reference to address with the building inspector on using 2 ground rods, 6 feet or greater apart, where Pex is used.


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## brric (Mar 5, 2010)

The reason for bonding metallic piping is to provide a low impedance path to trip a breaker should the piping become energized. It has nothing to do with a return to earth.


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## SD515 (Aug 17, 2008)

TROTZINKA said:


> You are absolutly correct, typo, min distance is 6 feet for locations where water lines can not be used as a bond.


Qualifying underground water pipes are not bonded, they are used as a grounding electrode. They also have to be supplemented with an additional qualifying electrode. If the supplemental electrode is a rod, pipe, or plate type, then it has to have 25 ohms or less resistance to ground (earth). If it doesn't, then an additional supplemental electrode has to be installed. [It's not whether a (as you put it) "water lines can not be used as a bond", it's whether the water pipe qualifies as a grounding electrode.] When we install ground rods, we usually just install 2. Verifying the 25 ohm rule can get expensive and tedious to prove to an inspector. Driving 2 rods is cheap and done. See 250.52 & 250.53



TROTZINKA said:


> Since you are in the know. Here is another question which I am not sure of.
> Bonnding to the gas line, where the supply to the gas meter's are now in plastic, in fact all the gas utility company's now run all their main lines in plastic to the meter. Is that bond still required or even relavent ? I have been doing it, just out of habit & and without question. But I truely wonder if it has been address in the code. My understanding, these bonds, basicly rely on going back to earth via the main line service supplied by the utility, weather water or gas. And thank you for correcting my screw up, 6 feet min is correct. And possibly you could address the question on the gas bond.


Metal underground gas piping systems are not permitted to be used as a grounding electrode, so the material used from the utility to the structure is irrelevant. 250.52(B).

250.104(B) states that other metal piping (including gas piping) in or attached to the structure has to be bonded to the electrical system.




TROTZINKA said:


> The reason for the reply to this older post was I was searching for a code reference to address with the building inspector on using 2 ground rods, 6 feet or greater apart, where Pex is used.


See 250.50. If the main water pipe is plastic, then obviously it can't be used as a grounding electrode. The system requires some sort of grounding electrode, and has to be installed if none exist. 250.52 list acceptable ones.


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## TROTZINKA (Apr 24, 2016)

Thank you for the explanaton, sometimes when dealing with an inspector, to have that knowledge


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## AllanJ (Nov 24, 2007)

If there is no gas appliance that uses electricity (and with a rigid gas connection and with a hard wired grounded electrical connection) then you run a bonding jumper from the gas plumbing to the grounding electrode system, possibly to the middle of a grounding electrode conductor running to a ground rod if that point is closest.

The bonding jumper is attached to a gas pipe downstream of the gas meter and there is no additional bonding jumper across the gas meter.

Still, this may result in bonding the electrical ground to the exiting gas pipe depending on the material of the gas meter but this cannot be helped.

One metal water pipe (if any) exiting the building and not known to run underground for fewer than 10 feet must be included as a grounding electrode where the grounding electrode conductor is attached within 5 feet of where the pipe exits and without any meter or other equipment in between..


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