I'm working with a GC to finish a walk out basement. Part of the project was to remove a wall. As I understand it that wall was put in place before the slab was poured, as a result there was some unevenness in the floor that might have been less noticeable had the wall been left alone. The GC's crew spent the better part of two days grinding down high spots in the concrete and poring a leveling compound to try to even out the concrete.

They are now in the process of laying LVP over the concrete. A brand called Rhino flooring that the GC seemed to want to use for various reasons over other products. I can't quite tell if that is a common brand or a house brand of a local specialty store. It has a thickness about the same as a SMARTCORE sample I picked up at Lowe's. This is thinner and less rigid over the length of the plank than the laminate flooring I have upstairs.

They've started to lay some of the LVP over the biggest area of the floor that needed leveled (about 6 x 15 ft) and there do seem to be a few spots where the unevenness of the concrete underneath is still apparent under the LVP. The surface looks fine ... it's not wavy, but there are places where when you step on it you can feel and hear it is a bit hollow underneath. It moves perhaps 1/8 of an inch. It may seem minor, but it kills the illusion of a solid floor, feeling more like kitchen vinyl sheet with failing glue.

I come from a house with real wood floors, not this fake stuff, So perhaps I am obsessing over something minor and this is the best that cn be done in this situation? Currently I think all the planks are floating. Would there be any value in going back and gluing down those areas, or would that make things worse? I'm guessing these pockets don't become apparent until you've laid one or two more courses past them. any other ideas?