# Ground Rod Installation



## BryanMD

Yeled said:


> Does anyone know what's the best way to drive an 8' ground rod into a rock?


I can't see that happening.
DRILLing a hole into rock for a rod to be set into? Maybe.



> I'm upgrading a service panel, on a house that was built on a bed rock.


Q: How was the grounding accomplished on the old install?
Q: What sort of foundation is there?


----------



## RGH

there has to be 1 spot somewhere around that foundation that you can smack that stick in....if not why not bury her 30" and ask for ok per 250.53 (g) as per code...ya got 30"s?


----------



## Cletis

*Rock*

I never had to it but I would think a big masonary bit with extensions first


----------



## HARRY304E

Yeled said:


> Does anyone know what's the best way to drive an 8' ground rod into a rock? I'm upgrading a service panel, on a house that was built on a bed rock. Tried using the Hilty with a ground rod adapter, but it doesn't move an inch... Any ideas??? Thanx.


Try to change the angle a little bit.


----------



## BBQ

RGH said:


> .if not why not bury her 30" and ask for ok per 250.53 (g) as per code...ya got 30"s?



Exactly





> 250.53(G) Rod and Pipe Electrodes. The electrode shall be in-stalled such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) *except that, where rock bottom is encoun-tered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, where rock bot-tom is encountered at an angle up to 45 degrees, the elec-trode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep.* The upper end of the electrode shall be flush with or below ground level unless the above-ground end and the grounding electrode conductor attach-ment are protected against physical damage as specified in 250.10.


----------



## electricmanscott

Yeled said:


> Does anyone know what's the best way to drive an 8' ground rod into a rock? I'm upgrading a service panel, on a house that was built on a bed rock. Tried using the Hilty with a ground rod adapter, but it doesn't move an inch... Any ideas??? Thanx.


 Not happening :no:


----------



## Wireman191

Cletis said:


> I never had to it but I would think a big masonary bit with extensions first


 Drilling a rock 8' down?:blink:
After a year and a half of drilling do you think the ground rod would be effective surrounded by rock?


----------



## Cletis

*rock*



Wireman191 said:


> Drilling a rock 8' down?:blink:
> After a year and a half of drilling do you think the ground rod would be effective surrounded by rock?


I didn't say it would be a good idea. In fact, it would be a horrible idea to burying a ground rod in a rock imo. I drill through rock all the time with carbide percussion bits and diamond coring/drilling bits


----------



## Southeast Power

Yeled said:


> Does anyone know what's the best way to drive an 8' ground rod into a rock? I'm upgrading a service panel, on a house that was built on a bed rock. Tried using the Hilty with a ground rod adapter, but it doesn't move an inch... Any ideas??? Thanx.


Bend a 90 on each end put a kick in the middle so it doesn't wobble back and forth too much and cover it up with sod.. It will be just as useful..:thumbsup:


----------



## Kevin23024

We are in the foothills of Los Angeles and run into this problem quite often. You would be amazed at the size of some of the boulders that can found here below grade. I know of some instances where they have had to change plans on a house because it was cheaper than trying to excavate and remove the boulder. 

Because of the granite bedrock here they actually require 2 rods min. 6' apart in the foothill areas. 

That being said we have never ran into a situation where we could not drive the rod. Although many times it has taken much longer than we wanted it to.

You have to pull it out and try a different spot. Multiple times if neccesary. 

Also try a fence post driver. Can be found at Home Cheapo for around $25. Thats what we use and I am a fan. No more busted nuckles. It has done the job for us when a Hilti bit couldnt.

There are no areas in LA tougher than were we are for this. What part of LA are you in?


----------



## Yeled

Kevin23024 said:


> We are in the foothills of Los Angeles and run into this problem quite often. You would be amazed at the size of some of the boulders that can found here below grade. I know of some instances where they have had to change plans on a house because it was cheaper than trying to excavate and remove the boulder.
> 
> Because of the granite bedrock here they actually require 2 rods min. 6' apart in the foothill areas.
> 
> That being said we have never ran into a situation where we could not drive the rod. Although many times it has taken much longer than we wanted it to.
> 
> You have to pull it out and try a different spot. Multiple times if neccesary.
> 
> Also try a fence post driver. Can be found at Home Cheapo for around $25. Thats what we use and I am a fan. No more busted nuckles. It has done the job for us when a Hilti bit couldnt.
> 
> There are no areas in LA tougher than were we are for this. What part of LA are you in?


Woodland Hills, up on the edge of Mullholand Dr. The ground is like concrete. I drilled with a concrete bit about 22" deep, got all the way in with my bit, but it's still rock. Wondering if i should get a much longer bit and keep on drilling... The current hole was made next to the new panel on the side of the house in concrete driveway.


----------



## Hairbone

I have ran into that problem with the ground rods before and have resorted to digging a trench the best i could a few times.

I came across this product recently and think it would be wise to look into for these cases: http://www.electricmotioncompany.com/emc.php?type=misc&sub=Lo-Ohm Grounding Cement


----------



## oldtimer

Kevin23024 said:


> We are in the foothills of Los Angeles and run into this problem quite often. You would be amazed at the size of some of the boulders that can found here below grade. I know of some instances where they have had to change plans on a house because it was cheaper than trying to excavate and remove the boulder.
> 
> Because of the granite bedrock here they actually require 2 rods min. 6' apart in the foothill areas.
> 
> That being said we have never ran into a situation where we could not drive the rod. Although many times it has taken much longer than we wanted it to.
> 
> You have to pull it out and try a different spot. Multiple times if neccesary.
> 
> Also try a fence post driver. Can be found at Home Cheapo for around $25. Thats what we use and I am a fan. No more busted nuckles. It has done the job for us when a Hilti bit couldnt.
> 
> There are no areas in LA tougher than were we are for this. What part of LA are you in?




Is it not permitted to use ground plates, instead of rods?


----------



## Amish Electrician

In order of 'power,' here are the ways to drive a ground rod:

1) SDS rotohammer;
2) Fence post driver;
3) Fence post driver, modified with guide sleeve and additional weight;
4) SDS-Max rotohammer;
5) 3/4 hex demolition hammer;
6) 1-1/8 hex electric jackhammer; and,
7) Hydraulic jackhammer.

Beyond that, you get to dig or drill. Machinery, such as a 'rock drill' or 'rock saw' is needed. If you're boring a hole, you need it large, as you will first pour in a wet mortar mix, then insert the rod. For a trench, ordinary sackrete will do fine. (OK, maybe not code-specified, but IMO worthwhile).

Code wonks haven't figured out yet whether a 20-ft. concrete 'sausage' laying on the rock, next to the house, qualifies as a "Ufer."


----------



## ptcrtn

This lightweight tool is designed for drilling blast, anchor and rock-splitting holes. Used for example by contractors, armies and utilities who want convenient and efficient drilling without large compressors. With standard integral steel, it drills diameters of up to 50 mm (2”) and depths down to approx. 6 m (33 ft) by using hydraulic power for impact and rotation. A small additional compressor is needed for flushing. Without airflushing, it can be operated wholly by hydraulics and can drill holes of down to 1 m (3.3 ft) with a spiral hammer drill.










I had to use this at an addition to Aluminum Plant. Built on bedrock. Had to put in about 30 ground rods for the building steel and ground ring. Filled holes with Electro-Fill™


----------



## Yeled

Thank you all for all your help. I actually drilled a 3/4" 3' hole through the bedrock and below that it was just dirt, so I drove it easily with my Hilty SDS max rotary hammer with the ground rod adapter. To comply with code, i've added another ground rod 8' away with the same technic. Figured 5' of the 8 is actually touching the dirt, so added another 5' and the inspector loved it!


----------



## BryanMD

Is tieing a service into bedrock of ANY electrical value or merit whatsoever?


----------



## Dennis Alwon

Yeled said:


> Thank you all for all your help. I actually drilled a 3/4" 3' hole through the bedrock and below that it was just dirt, so I drove it easily with my Hilty SDS max rotary hammer with the ground rod adapter. To comply with code, i've added another ground rod 8' away with the same technic. Figured 5' of the 8 is actually touching the dirt, so added another 5' and the inspector loved it!



You have a 3' Hilti Bit???? Yikes


----------



## woodchuck2

Sounds easier to dig a ditch and lay it in. My inspector once instructed me to lay the rod on the exposed ledge and concrete the rod to the ledge. I have only ever done that once and it was on top of a mountain.


----------



## Amish Electrician

Bryan, you raise a good point, one that has inspired endless discussion. Alas, for us the decision is made: code says so. 
I like Mike Holt's approach: Neutral bond for fault protection, ground rod for lightning and static. Electricity wants to go 'home,' and the only electricity that considers the dirt under our feet to be 'home' is static electricity. The stuff in our wires calls the transformer it came from 'home.' 

This point become very important when we introduce additional power sources into the circuit- be they generators, UPS battery banks, or solar panels. "Lost" electricity needs a path "home" for the breakers to trip.


----------



## BryanMD

Amish Electrician said:


> Bryan, you raise a good point, one that has inspired endless discussion. Alas...


Alas, nothing. Been there and done that. 
I wasn't raising that shibboleth again.

My question is about a rod set into rock vs into soil...
regardless of how long a drill bit the OP may have available.

The OP also avoided my first questions: 
1) about what the original installation used, and 
2) what sort of structure (if going for a Ufer might be possible)

hth


----------



## Whatevva

Ground Plate...


----------



## oldtimer

Whatevva said:


> Ground Plate...




Question was asked ..... post # 14.

No answer!


----------



## Yeled

BryanMD said:


> Alas, nothing. Been there and done that.
> I wasn't raising that shibboleth again.
> 
> My question is about a rod set into rock vs into soil...
> regardless of how long a drill bit the OP may have available.
> 
> The OP also avoided my first questions:
> 1) about what the original installation used, and
> 2) what sort of structure (if going for a Ufer might be possible)
> 
> hth


Hi Bryan,
To answer your questions
1. The original installation was using an 8' ground rod which was pounded to ground before concrete was poured for the driveway. I guess they also had to drill some depth to penetrate through the bedrock.
2. The structure is a single family home, 2 story high, laying on slob foundation. The house is located on the ridge of a mountain.


----------



## Yeled

oldtimer said:


> Question was asked ..... post # 14.
> 
> No answer!


Sorry, was busy to finish that job...

I couldn't use any plates because the areas all around the house were paved with concrete, in order to lay a ground plate I would have to break the concrete. Didn't want to do that unless I had to cause it is stamped and colored and repairing that would be expensive and most likely be noticeable.


----------



## BryanMD

Yeled said:


> 1. The original installation ...concrete ...driveway.
> 2. ...laying on slab foundation.


Thanks for the reply.
So, enquiring minds and all... what about the job of accessing either of those? 
Was that even considered?


----------



## Yeled

BryanMD said:


> Thanks for the reply.
> So, enquiring minds and all... what about the job of accessing either of those?
> Was that even considered?


What do you mean?


----------



## BryanMD

Yeled said:


> What do you mean?


The ideat that rather than reinventing the wheel by attempting to drill 8+ feet into bedrock or ledge 
(and who exactly is tooled up for that task?)...
to utilize what is already there like the existing ground and the foundation rebar.

Just wondering if the thought ever crossed anyone's mind.


----------



## Yeled

BryanMD said:


> The ideat that rather than reinventing the wheel by attempting to drill 8+ feet into bedrock or ledge
> (and who exactly is tooled up for that task?)...
> to utilize what is already there like the existing ground and the foundation rebar.
> 
> Just wondering if the thought ever crossed anyone's mind.


I couldn't access the original ground rod because they poured the driveway concrete on top of it, so I would have to break the concrete to get access to it, and I didn't want to do any damage to the concrete unless I would absolutely have too.... (the concrete is colored and stamped)
As far as the foundation rebar, I would also had to break some of the foundation to expose the rebar, thought it would be a better and cleaner idea to do it the conventional way, and I did!


----------



## Yeled

Hairbone said:


> I have ran into that problem with the ground rods before and have resorted to digging a trench the best i could a few times.
> 
> I came across this product recently and think it would be wise to look into for these cases: http://www.electricmotioncompany.com/emc.php?type=misc&sub=Lo-Ohm%20Grounding%20Cement


Thanks for the link.
I checked it out, but the problem is that I can not dig a trench anywhere close to the panel. If anything the closest place I would be able to dig is maybe the back yard which is about 70' away from the panel. I doubt if even that would be possible to trench... The ground there is very rocky.

Sent from my iPad2


----------



## varmit

Just a hypothetical idea: If a ground rod was concreted on or into a large rock (bonded to the rock ) would it be considered the equivalent of a ufer? Concrete is just a man made rock.


----------



## woodchuck2

That is kind of what i was getting at when i mentioned that one time my inspector had me concrete the rod to the ledge once. I do not see why it could not be done to the foundation, ledge or even part of a walkway/driveway if it is on ledge.


----------



## Elephante

Cut it in half and mushroom the top of the rod.Make sure to leave the writng on the side exposed.lol :O)


----------



## B W E

Yeled said:


> Woodland Hills, up on the edge of Mullholand Dr. The ground is like concrete. I drilled with a concrete bit about 22" deep, got all the way in with my bit, but it's still rock. Wondering if i should get a much longer bit and keep on drilling... The current hole was made next to the new panel on the side of the house in concrete driveway.


I would try drilling at an angle through the footing in to the house (under the house). Nothing like a nasty ground rod to screw everything up! I was just over there yesterday, mulholland and canoga area, up in the hills. I hope I never have to drive a ground rod up there. I don't even like driving a van up there!


----------



## captkirk

I got a long bit too. I was gonna suggest that too. Its a really handy thing to have around.


----------

