|
|
|
|
|
POST HOLES & TREE HOLE DIGGING - DRILLING |
|
DRILLING CONDITIONS Some areas out in the Texas Hill Country have either flint or dolomite. These two mineral varieties generally refuse to be easily cut, drilled, and hammered. Dynamite works! Seriously, many contractors I know have ruined the teeth on rocksaws and augers when they encounter flint and dolomite. There are known deposits of these rocks in Fredericksburg, Driftwood, and over toward S. Dripping Sprs. I managed to win the battle with flint with a rocksaw, but lost the fight with dolomite while using my rock toothed auger just north of Driftwood. I got down to one foot of depth quick, hit the dolomite, and then gained only 1 inch over the next hour of drilling. At that point I recommended to the owner that their money would be better spent if I went on to the next area of the project, and that they have us come back with jackhammer equipment at a later date. Jackhammer was the only thing that could work. So, why not just use that equipment all the time? The reason we don't is that the jackhammer creates messy holes that are not well defined and thus it can be difficult to install the fence posts. Also the holes end up taking a lot more concrete because of the irregular size and shape of the opening. In the hill country, we generally encounter hard packed caliche, dirt mixed with caliche, solid limestone and fragmented limestone. Our augers can handle any combination of these types of earth. Roots are a little bit more difficult because the augers are specially designed for drilling rock and hard packed dirt, and are not as efficient with tree roots. But bear with us, we will get through the roots when we encounter them.
|
|
