lowering basement floor
Has anyone done a major basement dig? I have a 5' crawlspace that i'd like to dig down to get 8'+ ceilings. Surely such a deep dig will go below the current foundation. Ideally, i'd prefer that my house not collapse.
The one contractor who gave a bid suggested that i use a "bench foundation" whereby a new foundation is attached directly inside the current foundation without disturbing the old one. this doesnt seem kosher to me. i would expect that underpinning is the way to go.
anybody have experience here?