Driving ground rod through rock

[strutaeng]

Hi guys, I'm wiring a subpanel to my detached garage. I laid out the conduit and will be wiring soon.

The area I live has caliche or limestone at about 12" below the soil. I was trying to drive my grounding rods but could only sink them about 18". Hitting it with a 10 # sledge hammer does nothing. I tried pre-drilling with the longest SDS max drill bit about 15" with no luck.

Do you have any tips for driving it down? I don't even think I can get them out now. They are stuck now.

 

[sberry]

Can it be bent over and buried?

 

[wyliesdiesels]

Hi guys, I'm wiring a subpanel to my detached garage. I laid out the conduit and will be wiring soon.

The area I live has caliche or limestone at about 12" below the soil. I was trying to drive my grounding rods but could only sink them about 18". Hitting it with a 10 # sledge hammer does nothing. I tried pre-drilling with the longest SDS max drill bit about 15" with no luck.

Do you have any tips for driving it down? I don't even think I can get them out now. They are stuck now.

Ive had to use a jackhammer to drive them into rock.

Can it be bent over and buried?

Cant bend over an already driven rod.

Code permits a rod to be buried horizontally at 30" depth. Would need to pre bend into 90* angle before burying.

 

[acer66]

Ground rod driver maybe?

 

[alfredeneuman]

Ground rod drivers are available for jackhammers. A 60# or even a 35# jackhammer will put a 10# sledge hammer to shame.
Under no circumstances should you just bend it over and bury it.

Plate electrodes and (ground rods installed horizontally) need to be buried a minimum of 30" when encountering solid rock.

 

[strutaeng]

Ground rod driver I can try. I just checked THD and they have them in stock. I hate to buy one for $50 and not work out for me...

I have a Bosch 1 5/8 combination hammer and a beat up 20 lb Dewalt demo. hammer.

Stay tuned!

 

[rlitman]

...I tried pre-drilling with the longest SDS max drill bit about 15" with no luck...

Wait, so you have an SDS max drill?

Ground rod driver maybe?

Exactly.

If you don't want to spend on a ground rod driver, just hacksaw off the end of a worn out SDS max drill bit, so you have a round shank to drive with, and slip a pipe ****** over the end to keep the ground rod from slipping off.

 

[wyliesdiesels]

Ground rod drivers are available for jackhammers. A 60# or even a 35# jackhammer will put a 10# sledge hammer to shame.
Under no circumstances should you just bend it over and bury it.

Plate electrodes and (ground rods installed horizontally) need to be buried a minimum of 30" when encountering solid rock.

Yeah whoops its 30" not 24". Thx

 

[rockwithjason]

I know your pain. Your best option here is the trench method. Home depot rents a demo hammer and rod driver bits. Honestly if the demo hammer wont get it then there is no hope of driving a rod.

 

[dw1]

If I cant get one in the ground with my Dewalt SDS Max and the ground rod driver (Sometimes a hit or three with a sledge hammer) is the ground like this all around your garage? sometimes just moving it over a bit can help, it doesn't have to be right outside your panel, try another area!!

 

[sberry]

I realize that bending them over isn't listed but wtf can you do here? I might give a call to the local inspector and see how they deal with it. You are probably not the only case in that area.

 

[tarmy]

Rent a 3' long bit for the sds...drill thru the rock part and use the driver bit after that...or get bit extensions until you get deep enough to fully embed...

 

[JunkBonds]

https://www.homedepot.ca/en/home/p.galvanized-ground-plate-cw-connector.1000423074.html

 

[79firebird]

any way you can use a ground plate? as i had to do that on a fue shops i have had due to being built on rock.

 

[alfredeneuman]

any way you can use a ground plate? as i had to do that on a fue shops i have had due to being built on rock.

By Code, the ground plate has to be a minimum of 30" deep.

 

[malibu101]

Reading this has me wondering 2 things....
1- If it is solid rock and one pounds, drills, or otherwise get a rod into the rock.
Will it "work" (meaning functional) as well as a rod would in soil?
2- If it has to be moved to an area without rocks.
Is there a maximum distance the rods can be from the panel?

 

[ishiboo]

If you don't want to spend on a ground rod driver, just hacksaw off the end of a worn out SDS max drill bit, so you have a round shank to drive with, and slip a pipe ****** over the end to keep the ground rod from slipping off.

Lol @ hacksaw an SDS bit. I took my Milwaukee bandsaw to one and it took the teeth off the blade in half a second with barely a scratch on it.

This is a job for a plasma cutter or abrasive. Those bits are HARD.

 

[jd_1138]

Um, rock ain't a good ground, because it is a lousy conductor. Gotta use a larger rod?

 

[rlitman]

Lol @ hacksaw an SDS bit. I took my Milwaukee bandsaw to one and it took the teeth off the blade in half a second with barely a scratch on it.



This is a job for a plasma cutter or abrasive. Those bits are HARD.

I know I’ve cut these bits before. I probably did it with an abrasive cutoff disc though. You’re right, it probably would eat the teeth on most hacksaws.

However a bi-metal hacksaw blade has much harder teeth than a carbon steel bandsaw blade with induction hardened teeth.

 

[sberry]

If there was ever a good question for a local inspection dept this is one.

 

[mm08822]

This would have been a good place for a ufer.

 

[lakeroadster]

I realize that bending them over isn't listed but wtf can you do here? I might give a call to the local inspector and see how they deal with it. You are probably not the only case in that area.

You can dig a hole....

and the 30" before going horizontal rule... the local inspector here was "lenient"...

2 ground rods

 

[2Big2Ride]

Hi guys, I'm wiring a subpanel to my detached garage. I laid out the conduit and will be wiring soon.

The area I live has caliche or limestone at about 12" below the soil. I was trying to drive my grounding rods but could only sink them about 18". Hitting it with a 10 # sledge hammer does nothing. I tried pre-drilling with the longest SDS max drill bit about 15" with no luck.

Do you have any tips for driving it down? I don't even think I can get them out now. They are stuck now.

I am apreciative our house is not on top of caliche. We can actually dig a hole with a shovel.

 

[sberry]

Yes one can dig a hole but the OP can't. That is the problem here. Engineering may be able to elaborate more on this but how much of a problem this could be is only a guess. Almost certainly less risk than traffic driving to the store getting materials for it or a couple trips to the rental store. Climate and susceptibility to lightening and static could be a factor.

 

[Fishingfoolemjak]

Here in the mountains, sometimes well only have 10 inches of soil before rock. Our inspectors will allow digging to the rock, laying the ground rod horizontal and then encasing it in concrete to the surface (grade).... they don’t like it, but it is the only way sometimes.

 

[Lelandwelds]

30"? Mine is zip tied to PVC, bent, and buried about a foot deep. I should add another ground rod?

It is solid limestone here and a PITA to drive a rod. I wish my electrician had put in the effort when all the equipment was here.

 

[James-W]

You could maybe call Harry Stamper to do the drilling for you.

 

[Lelandwelds]

You could maybe call Harry Stamper to do the drilling for you.

Lol. I am slow today. Had to google.

 

[lakeroadster]

Yes one can dig a hole but the OP can't. That is the problem here.

It certainly can be done.. what, are there no water wells anyplace there is rock?

Does the building have a foundation deeper than 12"?

It's a matter of what can be done, vs what wants to be done and a matter of planning.

Rent a jack hammer and have at it. That's what's done here for nearly every hole dug into the ground.

 

[James-W]

It certainly can be done.. what, are there no water wells anyplace there is rock?

Does the building have a foundation deeper than 12"?

It's a matter of what can be done, vs what wants to be done and a matter of planning.

Rent a jack hammer and have at it. That's what's done here for nearly every hole dug into the ground.

No doubt about it, most things can be done, but quite often the cost to do it makes it prohibitive. If there is an alternate way to do it that is acceptable, and is affordable, then what is wrong with going the alternate way?

 

[alfredeneuman]

No doubt about it, most things can be done, but quite often the cost to do it makes it prohibitive. If there is an alternate way to do it that is acceptable, and is affordable, then what is wrong with going the alternate way?

Acceptable to whom?
A consensus of mostly DIYs on an internet forum or of the Building Officials?
Hint:
It doesn't meet the minimum Codes
Unless the feeder to the garage is in Galvanized Rigid Conduit or IMC it's not buried deep enough either!

 

[Norcal]

Acceptable to whom?
A consensus of mostly DIYs on an internet forum or of the Building Officials?
Hint:
It doesn't meet the minimum Codes
Unless the feeder to the garage is in Galvanized Rigid Conduit or IMC it's not buried deep enough either!

Have to agree with this. To the OP, is this a existing, or new build?

 

[ard]

Here in the mountains, sometimes well only have 10 inches of soil before rock. Our inspectors will allow digging to the rock, laying the ground rod horizontal and then encasing it in concrete to the surface (grade).... they don’t like it, but it is the only way sometimes.

Like a stand-alone UFER....

 

[sberry]

Good catch on the burial depth if the service doesn't come in overhead.

 

[James-W]

Acceptable to whom?
A consensus of mostly DIYs on an internet forum or of the Building Officials?
Hint:
It doesn't meet the minimum Codes
Unless the feeder to the garage is in Galvanized Rigid Conduit or IMC it's not buried deep enough either!

Acceptable to the local building inspector, or whoever is the authority for checking work and passing/rejecting the inspection for your area.

 

[Lelandwelds]

30"? Mine is zip tied to PVC, bent, and buried about a foot deep. I should add another ground rod?

It is solid limestone here and a PITA to drive a rod. I wish my electrician had put in the effort when all the equipment was here.

Seriously guys. How big a deal is this? I dont plan on a lightning strike but who does? I have an extra rod. If I have to, I can break out the Bobcat rock drill. An 8" hole 4.5 feet deep might be a little overkill but will do in a pinch.

 

[wyliesdiesels]

Acceptable to the local building inspector, or whoever is the authority for checking work and passing/rejecting the inspection for your area.

Just because the local building inspector says its acceptable doesnt mean its right or is code permissable.

Inspectors miss things and pass non code permissible installations all the time.

 

[James-W]

So what are we supposed to do? We count on the inspector to check out the work and make sure it was done correctly according to code. If a mistake was made, we expect that the inspector will catch it and we will fail the inspection until we get the problem area fixed.

I have no idea how it is done in California, but around here, as far as I know at least, the inspector is the final authority in these matters. If the inspector OK’s the work as being satisfactory, then it is a done deal. If the inspector fails to pass the work for whatever reason, then whatever is wrong must be fixed and then re-inspected.

I would assume it is the same in most places, the authority having jurisdiction has the final say in-so-far as if the work is acceptable or not. If the inspector doesn’t know what he/she is doing, or if they are continually careless in doing their job and they overlook things that are wrong, then they should not be in that position.

 

[lakeroadster]

I would assume it is the same in most places, the authority having jurisdiction has the final say in-so-far as if the work is acceptable or not. If the inspector doesn’t know what he/she is doing, or if they are continually careless in doing their job and they overlook things that are wrong, then they should not be in that position.

Should a, would a... how you going to make that happen? Tell his boss and piss off the inspector that inspects your building? It's a slippery slope.

Case in point:

1. Read this.... start at post #12 Can You Review the 100 Amp Service For My Pole Barn?
   
2. The first inspection on my barn was depth of the holes. The inspection happened when I wasn't home. The inspector signed off on them. They were 1 foot to shallow. I had the GC dig them deeper to match the print.
   
3. One of the inspectors here is on every local business' **** list. I know because when we moved here we inherited his phone number. He was a GC, his business went bankrupt, he didn't pay his debts and now is the local inspector.
   
   He did the rough framing inspection for my barn. I was there by myself. I had the stamped drawings in hand.
   
   He walked into the building, with his plastic "crocs" shoes on, you know, the one's with holes in them, and looked at nothing. I asked if he wanted the drawings, or to use my ladder, he said no, signed the permit document and left.

So what you have to do is research, find out what is right, and make it happen.

That's what makes Garage Journal so valuable. You can get answers here, from folks like wyliesdiesels, pattenp and Norcal, and then ensure that the work on your building is done correctly.

 

[James-W]

Forget about the members of this forum, they are not like a normal homeowner. When a normal homeowner wants to do something, they hire an electrician, or a plumber, or whoever they need to do a job. There is usually a permit involved, which I think is a good idea. Having to get a permit means the work needs to be inspected to be sure it is done correctly. Homeowners have every right to expect that the person who will be doing the inspection knows how to do their job correctly.

For example, take my neighbor across the street from me. He and his wife are in their late 80’s. If he hires an electrician to add a couple circuits in his basement, he will expect the inspector to check the work and make sure it is done correctly. He and his wife know virtually nothing about electrical work and they sure aren’t going to go to a tech school to learn about it at their age. They, like most homeowners, depend on the inspector to know this stuff and to pass or fail the work according to the code. If the inspector comes in, checks the job and says it passed, how is the homeowner supposed to know the work was not done right? If the inspector says the work is acceptable, the homeowner did his/her part, hired a licensed professional, paid for a permit, the work was inspected and passed, so what else is the homeowner expected to do?