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.