Hello - I am looking to install about 1000 sq ft, of floating laminate flooring on the first floor (over a basement) of a 30 year old house. The subfloor is 3/4" tongue and groove OSB that was previously carpeted and appears to be in good in shape but is full of significant dips and peaks - upto 1/8+" in spots. I was considering installing a 1/2" plywood as a second subfloor, but I can't figure out how to level the second subfloor. I was planning to run the second floor in the same direction as the first, offset the 4x8 panels, and screw them down with 1 1/4" screws; however, the more I think about it the more I am convinced that I am going to end up with a second floor with the same peaks and valleys as the first subfloor. Is what I want to do possible or advisable? Is there a way to actually make this work / level? Your help is genuinely appreciated.