Just finished my house and it isnt even 7 months old. I was walking around and noticed several resonant spots that seem to have no filler dirt under them. ( I have stained concrete floors so every step is heard). I even noticed that at and exterior wall by a toilet, it resonates. Why would this be? It has not rained in a while but i am careful to wet my perimeter with a soaker hose. Should I do anything about it….CAN you do anything about it. If there is a problem what is the solution? I dont like this clay soil out here. I am unfamiliar with it and it terrifies me. I just moved up here from houston and the soil there was so much more,….predictable. I hear that this clay swells alot and falls alot.