hi , iv,e got a mid terraced property which has suffered from mining subsidence in the past , now all settled . but has left a fall from back to front of about 3 inchs which due to lay out is only really noticeable in the living room that is the full with of the house , and the door to room is at the low end. now to the plan . take a few boards up run a datum line round bottom of wall measure down and cut out the brick from under all joists and re-level, of course floor will be supported at the time . is this do-able or am i missing something . been plumbing /heating for looong time so used to building work but never seen it done . would appreciate someones opinion whose tried it . cheers.