I have concrete floors in my 1960's semi. I have pulled the carpet and stripped off what looks to be the original lino tiles. Towards the patio doors the last 500mm of concrete raises up by nearly 30mm in a slope and sounds hollow. There is a small crack where it starts to lift. I broke a hole in the floor next to th door and found a large gap between the floor and the rough concrete base underneath.
Any idea what could cause this? I am thinking of excavating a cross section but wonder if anyone has seen something like this before?
Thanks
Graham
Any idea what could cause this? I am thinking of excavating a cross section but wonder if anyone has seen something like this before?
Thanks
Graham