Comment by berniedurfee

I did that in a low basement once. I had to replace the crumbled concrete floor anyway, so I figured I’d dig it down a foot or two while I was at it… then I found out the house was sitting on a shale ledge.

Turns out excavating shale by hand or with a jack hammer is incredibly difficult! It breaks into tiny pieces, bit by bit. Then you have to shovel said pieces into buckets and haul them out. Really heavy buckets because rocks.

One of the few jobs I threw in the towel and hired out. It still took 3 people 2 days to dig out about 18 inches. Never again!