How to treat an uneven floor before installing LVP in a remodel

I am sharing a field experience in Renovation & Remodeling. I had been working on an occupied home remodel where the client wanted to move quickly when, upon lifting the carpet, it appeared that the floor had an unevenness that the LVP would mirror. The symptom that made me investigate it seriously was that the straightedge showed gaps, the door was rubbing, and the client thought the…