Unfortunately when caliche has been discovered and it's really bad at the start of excavation we may need to crane in larger hammering equipement. Caliche is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials-such as gravel, sand, clay and silt. When we encounter this your ground is classified as a hard dig because the excavator claw alone will not pierce the soil.
This will require the hammer attachment to loosen the soil by hammering and then be switched with the claw back and forth repeatedly. By doing this it slows the dig time down drastically. The soil is also considered hard to handle and we cannot dump it at our normal locations. It has to be taken to a special dump site which all costs more time and money to us. It is very unfortunate when this is encountered and even worse when it is an extreme case. Caliche will always put us way behind on multiple projects so we want you to know it's a bad situation for everyone.
If the soil is extremely hard it is possible we may recommend bringing in a 90 foot crane and craning a much bigger machine to hammer it over the house. This is if it won't fit down the side of your home. The larger excavator will allow us to hook up a hammer attachment that is 3 times the size of the one we use for the smaller excavator. When this is needed it speeds up the hammer time so we can get it done twice as fast hopefully.
We hammer and remove rock each day as fast as we can. If we crane in a larger excavator the crane will cost an estimated $3400 directly to the crane company paid by the homeowner. You will also be responsible for the hard dig costs which we can't guarantee how many hours it will take. We just have to do our best to break through it as fast as possible. We track hours each day and leave the hard dig sheets daily.
We do apologize about the added costs but the hard dig is something we cannot predetermine. A standard pool with no caliche or hard to handle soil will usually take 1 to 2 days max to dig. When we hit caliche or hard soil the dig can go on for weeks in real bad cases.
Please see attached photos of some examples of hard dig soil and craning over a larger hammer on this job, also a hammering video.