I'm in the process of redecorating the living room and when I lifted the laminate floor threshold strip by the front door I discovered a hole in the concrete. I put a tape measure in to measure the depth and it was approximately 18cm. The floor next to it looks to be flaking and I assume it's only a matter of time before it also progresses to a hole. So, a) what's happened and b)what needs to be done to fix it? Any advice will be gratefully received, it's one thing after another with this house.
I would suggest you get a Local builder in to look at it and check it out. Maybe something or nothing.
Possibly where the cavity wall is and whatever was put across there to bridge the gap in the past to support a surface finish has eventually broken down and dropped into the cavity.