Hello Everyone! This is my first post; however, I am a big fan of this website and have used the tips and recommendations from DIY.com for years. My question is this: What is the best way to level a sub-floor in preparation for laminate flooring installation? I am going to float a "click and stick" 12mm +3mm pre-glued underlayment laminate flooring. (Kensington Manor 12mm Summer Retreat Teak Handscraped Laminate) The sub-floor is 3/4" plywood nailed to 2x12 joists, spaced 16 inches. The sub-floor appears to be strong however along on the east and west walls, there is a dip in the floor that starts from 18 to 12 inches from the wall. The dip is anywhere between 1/4 - 3/8". I was considering one of two approaches to level the floor. Either use self leveling compound near the walls where the floor dips and sand the floor smooth and flat, or to build up the low spots with 1/4" ply and lay down another level of 1/2" plywood over the entire floor to ensure it is totally flat and smooth. I was wondering how the pro DIYers handle a situation like this without creating too much work for themselves while getting the job done right.

This is my first real DIY home reno project and I will be installing solid hardwood into a previously carpeted room, which will be my new office. According to some videos I watched, it is suggested to simply use building paper between the plywood and hardwood. However, I have also heard about placing material for moisture and sound barrier. Right now the hardwood is being acclimated, so I'm doing as much research as I can to get this right. From your experience, what underlayment should I use or consider to go along with my solid hardwood installation? [ATTACH]29846[/ATTACH] freshDIY