excavating limestone/bedrock

[CleverNickname]

What is the best way to do this? Rent a jackhammer and generator/compressor? Is there some way to use a concrete saw and remove slices at a time?

If you have to hire pros, how much does it cost?

A few years ago I read (wired?) about some cool tool that shoots nails at super speed at rock to break it up. I would so love to rent one of those. Does anybody know if it ever really came to market?

Relatedly, what is the price of aggregate (gravel)? Does it go by the ton, or by cubic yard? Sometimes the internet doesn't reveal good prices like I wish it would.

 

[Staley]

What are you planning, how much rock are you removing and how deep are you going? Is the rock solid or fractured? Where are you at?

Next, what type and size of gravel (pea gravel, 3/8", 3/4" or 1" washed rock, or crushed limestone gravel) are you looking for, and how much is needed?

 

[Thunderhoof]

Staley asks good questions there.

I have A LOT of experience with limestone excavation using anything from hand tools to pneumatic and electric tools to dynamite. I recommend the latter

.

It really all depends on the strata you are working in and how much of the stuff you need to remove.

 

[CleverNickname]

Simple project involving a napkin sketch. Half buried seabox, & earth berm.

Its pretty solid limestone typical of the hill country. About 1" of soil on top of the white stuff. Basically I was wondering if its a reasonable task (given a week or so, rented jackhammer, bobcat, a few hundred pounds of dexpan) to excavate something maybe 20' x 10' x 4'. Call it 30 cu yards.
If I could excavate that I figure I'd have enough rubble and aggregate to build the earth berm. I'm not really picky about the aggregate, so long as it drains. Cheap is good.

 

[Staley]

No way I'd want to attempt that type of excavation with a jackhammer. The first 6" to 1' will be weathered and break up fairly easily. The solid limestone underneath will not break easily with a jackhammer. My suggestion would be to rent a bobcat type loader that has a (quick coupler) so that you can change out between a bucket attachment to remove the material, and a hydraulic hammer attachment or "hoe ram" for breaking the rock.

Even with a bobcat type machine your still in for a lot of hard time consuming work. An even better idea would be to rent a backhoe loader that has a quick coupler with a hoe ram attachment. All of the local rental houses should have them. Just make sure that the bucket and hammer come with a quick coupler so that you won't have to beat the pins out with a sledge hammer each time you want to change between the two.

Most gravel and crushed rock will cost you between $6.50 and $10.00 per ton. Depending on pit and delivery location the haul can be anywhere from $2.50 to $7.00 per ton.

 

[Informed]

Just came across this thread. I was digging for a retaining wall for a pool and had a backhoe with a hydraulic jackhammer. I had some HOA issues and we had to return the backhoe while those were being resolved. Meanwhile, our neighbor wanted us to put the fence back up and do the yard repairs. So now, I have to do the rest of the dig by hand. Jackhammers are possible but are a pain in the butt for various reasons. I was thinking about purchasing a 10" core drill for about $700 that is on a rolling stand. I have lots of time available but I want the work to be somewhat easy physically. The jackhammer is slow, gets jammed and is pretty hard physically and is probably about $1500 for a 70lb electric jackhammer. I'm still going to have to wheelbarrow all the debris to the front of the house. Anyway for those who have done this a lot in limestone, what are your suggestions for doing it by hand in a residential area. I need to go down 2 ft. for the length of the pool (40ft.) and the hole probably needs to be about 3 ft. wide.