I have moved into a four in a block, top flat and all the floorboards squeak. The neighbours have complained even when we haven't been doing anything! I have a wooden floor overlayed in the living room and a carpet I would replace in the hall. Is it possible to lift and floorboards, put an underlay in and put them back? If so, is it an expensive job and would I be better just replacing the whole thing? I would replace the hall carpet but would like the floorboards treated in the living room and hall. thanks