We have a fibreglass pool going in, it appeared to go well until the water was in and it was backfilled ready for concrete when i noticed the step in the picture on the left is hollow and noisy to walk on, it actually flexes under heavy foot. The builders have been keen to fix it and have been on site trying hard, they have put plenty of the dust (crushed rock stuff) its improved a lot, but its not firm all the way along. Its concreted and paving has begun.
Is it possible to pack this up properly without major re excavation? The guys seem to be trying to sort this with the last amount of re work,e g concrete replacement through small holes in the concrete.
I am concerned they will get it right now and then summer and winter will come and go and it will settle a few millimetres and the issue will return, this time with paving on top.
The ground is very hard dry clay and its not a majorly wet area of the yard. I think they made the hole too big and didnt back fill properly.