I've moved into a recent conversion (completed 1 year ago) and I suspect the contractors have skimped in a number of inportant areas.
Example- they've concreted the yard outside the back door and inserted a new man-hole sewage cover and the surface is becoming increasingly pitted with holes 1-2inches across in places and up to 1inch deep. The edging has broken down around the man-hole cover which is now loose and a tripping hazzard. If I put a stick into the developing holes and twiddle it around I get sand and bit's of gravel coming out and the area never properly dries out (the yard never get's direct sun) and it's proving difficult to maintain. Whenever I attempt to sweep up I get a load of sand and grit. It's looking like a Moonscape.
Any suggestions as to why the concrete is degrading like this? I think they didn't use the right mixture in an attempt to save on the concrete and/or they simply didn't know what they were doing. You should see the rest of the place!