main wood floor unlevel
8 years should not ordinarily result in a significant deflection of the floor unless there is a problem.  Figuring out the problem and how to correct it may involve several professionals, depending on exactly what is wrong and how much work you need to do: structural engineer, architect, soil testing, carpentry, painting, etc..., and you could wind up needing someone to manage insurance claims or deal with legal issues.  It may be as simple as having a GC replace a failing support or as complex as a major erosion problem or faulty building design.  

The first thing to do is find a reliable general contractor and have them look at the house.  Before hiring anyone to do major work, talk to and get bids from multiple contractors.  The second contractor may realize something the first didn't, and competitive bids ordinarily save you a substantial percentage of the price.