I am replacing downstairs flooring that had three layers before the subfloor. Linoleum, Cement Board and Tile. All flooring had to be removed down to the subfloor due to water leak. Since the cement board was screwed it, it is causing uneven areas as the screws are pulled/removed. Should I lay 1/4" or 1/2" plywood underlayment on top of subfloor before installing LifeProof vinyl plank flooring?
If so, what do you recommend? Should I also glue this new underlayment on current subfloor and screw down as well?
The goal is to not have any transition pieces from room to room, while making sure flooring is level with no dips or valleys.