Hi Folks,
First post here for me, I am hoping one of you can help us. We just poured a 1.5" layer of concrete as a suspended slab in our 110 year old house to cover the radiant tubing we installed as part of the reno upgrade. Our engineer tells us the floor assembly is more than strong enough for the concrete. Today is our first day walking on the floor and we can feel a vibration moving through the floor when someone walks on it. The vibration is only felt when standing still while someone else moves around and we are worried that it will be very aggravating while reading, sleeping and eating when there is house activity. Up until this point we had planned to do a glue down engineered hardwood flooring however with this vibration surprise I am wondering if we would be better off with a floating floor. I should add that right now there is nothing in the house as the entire main floor has been gutted for the reno and that this will likely make the vibration worse than when it is full of cabinets, furniture and area carpets. For you experts out there: will adding other stuff reduce the vibration? Will glue down wood change the vibration? Should we go to a floating engineered wood floor with some type of dampening underlayment (remembering that we are heating with in floor hydronic radiant heat)?

First I'd speak to the engineer about the vibration and see what he thinks.