TLDR; What should a quality LVP floor installation feel like? Is it reasonable to have few barely noticeable soft spots? or should entire floor feel consistently solid through the entire area?
I had a CoreTec Plus LVP installed (7" x 48" vinyl planks) over a concrete subfloor. It is an interlocking floating floor. It was installed in place of glued down carpet.
Installer did remove the carpet and did scrape the floor. They did put thinset in one place. However there are few spots (including one where thinset was used) that feel soft, and I can see floor flexing as I step on it. Sound also changes as I walk on it. Most of the area feels rock solid though.
Installer claims that floating floor will always have soft spots, and that he has done a quality job per manufacturer's instructions and specifications.
My question is, before I go ahead and hire a certified floor inspector, how can I determine whether installation hasn't been done properly, or if I am being too picky about it?