Digging in lava

[melo1112]

Is it possible to dig holes in lava by hand to set poles and post ? If not ,what is the best technique ? I am coming from the east coast of the mainland and would appreciate any advice.

[JerryCarr]

There are drills and jackhamers availble at rental agencies in Puna for such jobs. If you don't have electric service at your location, you will need a generator as the drills are electric. The jackhammers I have seen have gasoline (or sometimes diesel) engine power. Puna Rentals in the Shipman Industrial area has these and will brief the customer on their use. Drills are used for smaller post holes and jackhammers for bigger ones.

This is hard, time consuming work. Even though my partner and I understood how to do it, we decided to hire out the job. The excellent guy (Kawika Stevens) who built my fence used metal posts for the most part with larger treated wooden ones at intervals for stronger anchor points. Four years later my fence is still rock solid.

Cheers,
Jerry

[Bullwinkle]

I bought one of those cheap chinese ebay jackhammers on impulse, The shipping priority mail more than the purchase price - about 300 for both I think.

Best tool purchase I ever made, used it most recently to "set" one of the home depot reflecting pools for my neighbor.

A jackhammer and an O' O' bar are indispensable up here at camp runamock

rattttt tat tat rattttttt tat tat

http://cgi.ebay.com/HD-DEMOLITION-ELECTR...53dc6864f9&_trksid=p3286.c0.m14#ht_2136wt_939

[DanielP]

If you are into buying such a tool, I would suggest that you consider a rotary hammer drill which has the capacity to hammer only as well as hammer drill. Mine is a Bosch and is a dream. Drill bits up to 1 1/2"x 18" long.

Dan

[MarkP]

I tried to dig a post hole for a gate post in pahoehoe using a small to medium sized hammer drill and an o'o. I gave up. I was making some progress but is was extremely slow going. I think that a larger drill would have made enough difference to keep me going. In fact, if you are going to do it right I would buy a dedicated jackhammer.

A friend of mine cast concrete gate posts using sonotubes. He cleared away all the rubble down to solid rock and drilled into the rock. Somehow he fixed the rebar into the rock either with epoxy or cement. Either way, if you are building on top of a sizeable piece of rock and if you have truly fixed the rebar into said bedrock, then you just achieved the largest possible footing for your post. Why dig out solid rock only to replace it with solid concrete? The answer would be it there was no rebar in the rock. If however you find a good way to set the rebar in the rock then you get around that and can take advantage of what would otherwise be an obstacle.

[Bullwinkle]

Im digging in solid "blue rock" out here ... find it has many fine fractures ... chasing those fractures with a jackhammer causes the rock to fail and fracture. If it wasn't for that my life would be pretty miserable. I am in the middle of jackhammering out a a bunch of it (15 cubic yards or so)

fence post no biggie,

When doing a habitable space, I think my vote would be for an excavated oversized reinforced concrete footing

[Sandra A.]

I probably should have read all posts first...but I caught the blue rock mention. Do you know that blue rock will actually "bust up" with a simple O'O bar? I know, it's easier with a backhoe using a hammer (hoe ram)...but, I know from experience that you can slam an O'O bar over & over and that blue rock will "bust em up" and with "smoke" yet...you will know it's blue rock when you see the smoke. Just recently my neighbors and I took turns digging 6 holes for 4X4's in my yard for the new huli-huli pit structure...blue rock-city. Three of us sweating, panting, handing over the bar, but we got her done. It is bust-able without a jack hammer, or any other implement, humans can do it...and it's such good therapy for me anyway []

[Sandra A.]

Oh and I am ALL ABOUT concrete...concrete...love it!

[Kapohocat]

Sandra - check this book out "Concrete at Home" by Fu-tung Cheng. Great pics!

Catherine Dumond
Blue Water Project Management
http://bluewaterprojects.blogspot.com/
808 965-9261
"We help make building your dream home a reality"

[Sandra A.]

oh thanks..I'll check it out on Amazon maybe []

Also checked your site, good info there. A "new to Big Island" owner-builder can get good initial info there before starting up. Many aspects of building here have zero to do with the mainland methods.