I am having an extension to the back and side of my house. The builders have laid a screed covering and then on top of that they put a thin layer of self levelling / smooth finish.
The problem I now have is that after a few weeks there a are many cracks appearing over the floor and there appears to be some small movement when you walk on the cracked areas.
I put a screw driver into one of the cracks and it went straight through and the screed underneath is just loose?
Looks like they have not been put down properly?
Any ideas on a course of action? Who should I get in to inpsect it (apart from builder)?