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-   -   Wood Patio Cover Post Grounding (http://www.diychatroom.com/f18/wood-patio-cover-post-grounding-47601/)

Madracki 06-27-2009 01:26 PM

Wood Patio Cover Post Grounding
 
My local building inspector (Yorba Linda, California) tells me I need to ground all 3 of the wooden post footing brackets to a ground rod with #8 wire. I've never heard of anything like this, he wants a 3ft ground rod pounded into the soil and the wires run from it to all 3 of the footing brackets that are set into 2ft deep holes w/conrete. He says it's for lightning protection. I can't find anything is the state building code about this. He also mentioned in passing that the pool rail for my swimming pool should also have the same grounding. Any thoughts on this?

J. V. 06-28-2009 11:11 AM

He's an idiot IMO. But you must do what he wants. 3' ground rod? What, your supposed to cut one. They do not make 3' ground rods. One more thing. If any bonding occurs on your property it MUST return to the service bonding system. Meaning it must go all the way back to the main service ground rod or grid. If you have a sub panel or disconnect closer that is bonded correctly you can go there. If he did not tell you this he should be relieved of his duties yesterday. He has no clue what bonding means and he surely has no experience with lightning suppression.

220/221 06-28-2009 11:57 AM

Are these post anchors within 6' of the pool?

If so, they may need to be bonded to the pools rebar, metal fencing and all the other metal stuff.

Ground rods aren't going to do anything. :wink:

Lightning protection ??:jester:

Stubbie 06-28-2009 12:46 PM

If he is saying that all three need to be bonded to the pool equipotential grid as 220/221 mentioned he is correct if they are within the required minimums of the waters edge.

3' ground rods would be ridiculous in your soil out there and what exactly is he trying to protect from lightning....the post??? Maybe he is worried the footing will crack if hit by lightning......:)

IMO he is wanting the posts bonded because of the pool and that is why he is saying use #8 awg copper to bond them. That is the required size for pool bonding of the equipotential grid.

What is puzzling is the ground rods. If you do not extend the #8 to the other bonded metal around the pool he is actually making things less safe in the event of an unwanted voltage gradient passing through the soil from an external electrical fault to earth such as lightning brief as it may be.

The ground rods IMO are not needed and I've never heard of them being required on any post brackets for protection from lightning. If he can't show you why these ground rods are required I would defer to the local AHJ for a ruling on installing them. For the life of me I can't understand their purpose as you are being instructed to do.

Madracki 06-28-2009 02:35 PM

Further Details...
 
2 Attachment(s)
The pool and concrete deck was in when I bought the house 2 years ago. The house is 30 years old, the pool about 25. The patio cover posts are within 6' of the pool. I had 3, 12'' squares cut in the deck (per the city) so I could set the posts in the existing deck and have room to dig the post hole and add brick trim. (see pictures)

The normal pool setback for the posts from the edge of the pool would have been the depth of the pool plus 12''. The pool is 3' deep in the shallow end, plus 12', would have given me a 4' setback, but they allowed me to only have a 3' setback if my footings were 24'' deep - something to do with the load on the pool's bondbeam. I went with the "city standard" design for the cover, or I whould have had to pay to have plans drawn up and pay for structural engineering checks, so I chose to go with the city standard. There is no rebar or any other electrical panels available without cutting the deck to get back to the pool electrcal panel at the other end of the yard. I assumed the wood posts were grounded to the 18'' steel brakets, which were then set 12'' into the 24'' holes (the bottom 12' of the hole was just filled with concrete), but I guess concrete is not a ground. Also, this is Southern California, we don't have lightning here to speak of. I thought he was worried about electrollis or something like that.

I think the ground rod suggestion was all he could think of because this is not new construction and there isn't access to the pools rebar etc. He also said the rail by the steps should also have been grounded when it was installed. It too had been added after the pool had been built, but is not part of this Permit.

Thanks for your help,

Tom

220/221 06-28-2009 05:06 PM

Yup. The post bases must be bonded but driving a rod will do nothing.

If thats what he wants, just do it. :jester:

It sounds easier than running the ground back to the service or pool equipment.


Oh crap....it's already finished.


How about this. Install some kind of non conductive covering around the post bases. Get a roll of pipe wrap and wrap it up past the metal.?? Trim out the bases with wood??? That should/may bring it into compliance.

If that fails you will have to run exposed wire back to the pool equipment or panel. It will be ugly (until you remove it after inspection).

Jim Port 06-28-2009 09:23 PM

Not knowing the difference between grounding and bonding and he calls himself and inspector?

You could ask to apply the exception in 680.43 Exception 1 and see he he will be ok with that. Yes that is in the Artcile for spas and hot tubs but maybe he will consider the concept the same. Or just wrap the post base with wood to cover the metal.

Stubbie 06-28-2009 09:30 PM

That inspector is really being silly, if you can't get a bonding wire to the pool pump bonding lug or some other point on the equipotential grid of the pool you are accomplishing nothing. I'm starting to think he thinks you are grounding the metal brackets to earth and this is doing the same thing as the pool equipotential grid. If you cannot bond all the metal around the pool together you will have a difference of potential existing and will have done all that silliness with the ground rods for no gain in safety.

I like 220/221's suggestion about making the metal brackets unaccessible to human touch and see if the guy will accept that.

Any way to go up the posts and get to the pool pump bonding lug with a #8 and make it look good??

Madracki 07-04-2009 01:27 PM

Well, I was well armed with all your comments/suggestions and the Inspector showed up (a rent-an-inspector the city is using) and basiclly says, "nice job" and signs off on the permit...

Bottom line is that I learned that there is a National Electrical Code that covers everything electrical, including grounding of all equipment within 5ft. of a pool. It clearly spells out about pumps, ladders, heaters etc. but there actually is nothing about wood patio covers. (Section 680)

Thanks for all your help, great site!!!

Tom Madracki

Stubbie 07-04-2009 02:48 PM

What the code is really wanting is bonding of all metal within 5' of the waters edge, this happens to include the pool equipment. Those metal brackets on the posts technically are required to be bonded to the pool equipotential grid if within 5 feet. The whole idea is if you were to touch two metal objects the bonding has brought both pieces to the same potential and without a difference of potential (voltage) current cannot flow and you will not receive a shock or worse.

Anyway glad your problem is resolved. I would still do as 220/221 suggested and cover the metal so that they cannot come in contact with people.

Stubbie 07-04-2009 02:49 PM

What the code is really wanting is bonding of all metal within 5' of the waters edge, this happens to include the pool equipment. Those metal brackets on the posts technically are required to be bonded to the pool equipotential grid if within 5 feet. The whole idea is if you were to touch two metal objects the bonding has brought both pieces to the same potential and without a difference of potential (voltage) current cannot flow and you will not receive a shock or worse.

Anyway glad your problem is resolved. I would still do as 220/221 suggested and cover the metal brackets so that they cannot come in contact with people.


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