Hardwood floors installed over zipcrete

Q: I live in a condo and recently had hardwood floors installed in my kitchen and living room. The contractor used nails versus glue. The original floor in my kitchen was vinyl and under the vinyl is zipcrete. I was told by another contractor that my floors should have been installed with glue and not nails and that my hardwood floors will not stay secure.

Is this true? If so, what should I do to correct the problem?

A: It is my understanding that zipcrete is a self levelling type cement. Being a condo, I have to assume under that is a concrete slab. I would think it impossible to nail to this floor. Gluing may or may not work either, depending how well the zipcrete has bonded to the floor beneath it. A few pieces of flooring would need to be glued to it and left to dry to test the strength of the compound. Best, safest way is to float a floor over it. If you really like a wood look rather than laminate, I would suggest a Torlys product. They do have long strip with a real wood veneer. This product is not like a typical laminate that consists of joining panels. Once the Torly’s strip is installed, it would be difficult to know if it was or was not solid wood.