This year we had an extremely reputable builder construct a new steel framed building, the whole project has been perfect except the concrete apron. We have cracks right across in 8 places, although these have been cut and filled with mastic it looks very untidy and several people have said we should not accept it. Builder says it's because of the hot weather and that concrete will crack no matter what precautions but I now look at every piece of concrete I walk over wherever I go and have not seen anything like this. Any advise would be much appreciated, the last thing we would want to do is fall out with the builder but at the same time this is probably the worst bit of concrete on the farm and he so far doesn't seem that interested. Can these cracks be cut out and re- concreted?