Grounding to Water Pipes- Electrical Inspections

Home Inspector with NCW Home Inspections, LLC

Grounding to Water Pipes- Electrical Inspections- Wenatchee and Quincy Home Inspections

When performing a home inspection and evaluating the electrical system I am always trying to confirm if a grounding system is proper.

The Washington State Home Inspector Standards of Practice states (WAC 308-408C-110 Electrical system.)-
A home Inspector must:
(b) Report (i) The existence of a connected service-grounding conductor and service-grounding electrode when same can be determined.  (ii) When no connection to a service grounding electrode can be confirmed.

The purpose of the grounding electrode is to be connected to earth and to the electrical equipment so it establishes a zero difference of potential between the earth and the electrical equipment. This zero difference of potential helps stabilize voltage for the electrical system.

In addition the grounding electrode system is used to limit the voltage imposed on the electrical system by lightning, line surges, or unintentional contact with higher-voltage lines.

Now during a home inspection it may not be easy to locate and I may not find it. Grounding electrodes can be buried and often not visible.

In many older homes it is common to use the water pipe as the primary grounding electrode. But often not within 5 feet of the entrance of the home.

                           Proper Grounding using water pipe -Wenatchee Home Inspection

The National Electrical Code states (per 2005/2008 NEC)-
250.52 Grounding Electrodes.   (A) Electrodes Permitted for Grounding.  
(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.

There is a good reason for the 5 foot rule. Often in these older homes the plumbing has been modified and replaced with materials that are not conductive such as plastics. Also you want to make sure that if you have a removable component such as a pressure reducing valve or meter etc… that you do not lose ground during replacement or servicing.

Here we have a perfect example of why this rule is so important. On this home inspection I found the ground has been severed when re-piping was performed. This home is now without a ground and is a safety issue.

                               Grounding lost from re-piping Quincy Home Inpections

Being “Grounded” is always a good thing.

“A shocking occurrence ceases to be shocking when it occurs daily. “

Alexander Chase

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service          509-670-9572

Comments (28)

Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Eric, Thank you very much.

Jay, That is rare.

Reuben, I run into this fairly frequently on these older homes.

Oct 23, 2012 11:39 PM
MaryBeth Mills Muldowney
TradeWinds Realty Group LLC - Braintree, MA
Massachusetts Broker Owner

This is an issue I am seeing more frequently in our area as water meters are replaced and the use of pvc piping becomes more common place.

Oct 23, 2012 11:43 PM
M. Lynn Delatte
Developers Realty - Broadview Heights, OH
Thanks for the information.
Oct 23, 2012 11:45 PM
Travis "the SOLD man" Parker; Broker/Owner
Travis Realty - Enterprise, AL
email: / cell: 334-494-7846

Being “Grounded” is always a good thing.

Yep - as a musician in various types of bands using electrical equipment, I can testify FIRST HAND that this is an important issue - and I'm just the drummer!

Nice to see that you caught that for the house!!

Oct 24, 2012 12:18 AM
Rob Renk
Center Street Lending - McKinney, TX
AE | Fast Fix/Flip Loans for Residential Investors

Thanks for the heads up on grounding.

Oct 24, 2012 01:26 AM
Bob Miller
Keller Williams Cornerstone Realty - Ocala, FL
The Ocala Dream Team

Hi Donald, almost everything here in Florida is PVC now so a separate ground rod is required.

Oct 24, 2012 01:35 AM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Marybeth , this is very true. All newer connections are plastics now.

Lynn, You are welcome

Travis, I hear you I was a musician for many years (Bassist), I can not recall how many time I have been shocked. I played in many of the older clubs where you never knew what you would get for power supply and grounding.

Rob, You are welcome.


Bob, Do you see UFER (using the foundation rebar) grounding down there also?

Oct 24, 2012 03:40 AM
Jeremy Wrenn
Winslow Homes - Youngsville, NC
VP of Finance, Winslow Homes

Donald, this is so far over my head!  I'm glad I don't have your job.  :)

Nice post!  Congrats on making the Daily Drop!

Oct 24, 2012 04:51 AM
Ric Mills
Keller Williams Southern Az - Tucson, AZ
Integrity, Honesty, and Vast Real Estate Knowledge

Great info for everyone.

Oct 24, 2012 05:47 AM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Jeremy,You really do not need to understand the physics behind it all but the basic principle, you need a good ground ; )

By the way thanks!


Ric, Thank you.

Oct 24, 2012 07:06 AM
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

Every now and again find the ground clamp laying on the ground. Corroded through or removed. 

Oct 24, 2012 10:20 AM
Gary L. Waters Broker Associate, Bucci Realty
Bucci Realty, Inc. - Melbourne, FL
Eighteen Years Experience in Brevard County

Interesting information here. This is not something I have run into as most the homes I sell are a few years old - not enough time to deteriorate and not enough time for a DIY to mess up the initial ground!

Oct 25, 2012 01:08 AM
John DL Arendsen
CREST "BACKYARD' HOMES, ON THE LEVEL General & Manufactured Home Contractor, TAG Real Estate Sales & Investments - Leucadia, CA
Crest Backyard Homes "ADU" dealer & RE Developer

Lot's of good info.

Oct 25, 2012 02:53 AM
Jon Quist
Tucson's BUYERS ONLY Realtor since 1996

The grounding process around here is a challenge with almost all newer homes. Hard to ground to a metal pipe when the house is plumbed with plastic pipe. Requires a different type of ground. Separate ground rod.

Oct 26, 2012 04:53 PM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Jim, Had one the other day that was corroded and broken.

Gary, If you are dealing with mostly newer inventory you will not see this issue much. Though I have seen poor grounding techniques done.

Oct 27, 2012 01:15 AM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

John, Thank you.

Jon, On most of from the 60/70's forward will have ground rods.

Oct 27, 2012 01:16 AM
Brad Baylor
ERA Coup Agency - Milton, PA

Donald - As you mentioned, the main issue I see with proper grounding is when the plumbing has been replaced, or partially replaced with pex or some other non-conductive material.

Oct 30, 2012 12:01 AM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Brad, This becomes pretty common when you are re-piping older homes.

Oct 30, 2012 12:28 AM
Wayne B. Pruner
Oregon First - Tigard, OR
Tigard Oregon Homes for Sale, Realtor, GRI

It was an accepted practice to just ground to the water pipes. Now, with good reason, grounding rods are required. Any updating requires a rod to be installed.

Nov 27, 2012 12:38 PM
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Wayne, It is a good idea to even supplement water pipes with ground rods. Can not have enough good grounding.

Nov 27, 2012 12:42 PM