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Lighting rod advice

Posted by storre (My Page) on
Fri, Jun 11, 10 at 16:49

I have a lightning rod question maybe someone can answer. I live on the top of a mountain and have lighting parts of the year but never had any problems. Now we are adding a new addition to the house. A second floor and the skeleton of the structure is iron, which will be covered with granite. The roof will also be iron on the main supports. The iron will enter the ground at 8 points around the structure with 8 I beams that are 6 meters long.

So my question is: It looks like I'm creating a lighting rod but they are iron and not copper and not touching the earth directly. They are in concrete footing about 1 meter deep. Should I put in a lighting arresting system separately or can i attach a wire to the bass of one or all of these vertical I beams and ground it that way? Or is it ok the way it is? I've put some pictures up here to see better.

http://justclick.net/house/IMG_9382.jpg
http://justclick.net/house/IMG_9385.jpg
http://justclick.net/house/IMG_9386.jpg
http://justclick.net/house/IMG_9388.jpg
http://justclick.net/house/IMG_9392.jpg
http://justclick.net/house/IMG_9397.jpg
http://justclick.net/house/IMG_9399.jpg
http://justclick.net/house/IMG_9401.jpg
http://justclick.net/house/IMG_9402.jpg


Follow-Up Postings:

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RE: Lighting rod advice

"It looks like I'm creating a lighting rod but they are iron and not copper and not touching the earth directly. They are in concrete footing about 1 meter deep."

Concrete conducts very nicely.

Your iron structure is already well grounded.

The reason we use copper down wires is for the low resistance of copper.
Your large steel sections will have a resistance that is more than low enough.

Steel frame buildings with concretes footings do not require any additional grounding.

Concrete buildings can have problems wit the non-earth contact upper floor concrete not conducting well.

In this case the rebar is bonded to create a path down to the ground contact footings of the building.

I worked in a building were we lost all sorts of radio gear on the roof repeatedly.
We started investigating and found the rebar had not been bonded.
A few very large down lines from the antenna ground plate on the roof took care of the problem.

If the iron frame is completely covered with granite you may not attract many strikes anyway.


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RE: Lighting rod advice

Wow that is great news. I was unsure of the conducting ability of concrete. The iron is well connected to the concrete also. It has a net of thick (probably 1/2" rebar) in the footing which is about 3'x3' and then the rebar is connected to a riser of the same type of rebar and then a heavy metal plate with 4 metal feet soldered to it is set in that rising network of rebar and the whole thing is incased in cement and then the beams are welded to that. Really a strong structure and connected to itself throughout. It will be covered with granite but not for about a month so didn't want to have a problem. Thanks a lot!!!! I put up 4 new pictures to show what i'm talking about:

I have a lightning rod question maybe someone can answer. I live on the top of a mountain and have lighting parts of the year but never had any problems. Now we are adding a new addition to the house. A second floor and the skeleton of the structure is iron, which will be covered with granite. The roof will also be iron on the main supports. The iron will enter the ground at 8 points around the structure with 8 I beams that are 6 meters long.

So my question is: It looks like I'm creating a lighting rod but they are iron and not copper and not touching the earth directly. They are in concrete footing about 1 meter deep. Should I put in a lighting arresting system separately or can i attach a wire to the bass of one or all of these vertical I beams and ground it that way? Or is it ok the way it is? I've put some pictures up here to see better.

http://justclick.net/house/IMG_9282.jpg
http://justclick.net/house/IMG_9300.jpg
http://justclick.net/house/IMG_9308.jpg
http://justclick.net/house/IMG_9309.jpg


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RE: Lighting rod advice

If you want some comforting reading search on "Ufer ground".

Rebar in concrete can be a very effective ground.


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RE: Lighting rod advice

Thanks Wayne. Looks like we did an ufer ground system without even realizing it :-D


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RE: Lighting rod advice

Dark gray granite... and BAMBOO... and red barrel tile roof... and flora that suggests sub-tropical island... I *MUST* know where this is located, because I've already run out of guesses... lol.

Thanks in advance.

PS: I think by "iron" you mean steel. Rebar work looks very good; if concrete is of similar quality you should have a very sound structure. Best of luck. It's ALWAYS an adventure. ;')


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