We pulled up the carpet in our family room that has a vinyl floor over a wooden subfloor with the plan to lay a laminate over it that has a pre-attached pad. I am afraid to get into removing the vinyl as our house is about 60 yrs old and I am concerned about it having asbestos backing- especially since I have a son with asthma. Problem is once we pulled the carpet up we found that the floor is visibly uneven. I know I cannot lay a laminate on an uneven floor. Any suggestions for leveling?