On Wed, 11 Mar 2015 10:32:05 -0700 (PDT), wrote:

I have a very tight crawlspace that needs to be lowered to at least 24". It's very hard clay so a tool to break it up would be a great idea. Anyway, I've been researching and it seems to be common practice to excavate an external opening and dig out from there. However, I was wondering if I could pull up the floors (which need to be replaced due to mold issues anyway) and access the area from above. One problem I see is getting around the floor joists to dig. Would I be able to move them out of the way (remove/replace them) as we go or is that a bad idea? Are there other concerns I need to consider? Its not a very large area and it has deep footings so I don't think 2 feet down will destabalize them.
When my brother was faced with that problem he got in underneath with
a shorh shovel and started out on his belly filling a bucket which his
son pulled out the "window" to the outside. When he got apace big
enoug to stand in he laid 2X4s as a "track", and with a pulley and
rope dragged the bucket out the window when full. Luckilly the city
was doing road work out front so he had no problem disposing of the
"fill" removed. It took him a couple weeks of "spare time" to get it
dug out.