we bought a house about 6 months ago. The house is 50 years old this year. Passed main and termite inspections with only minor issues (many of which we've already addressed), and also had an inspection from the insurance company.
I noticed when we moved in that our furniture in a few rooms on the second level is not level. I checked the floor with our bubble level to see what was going on. In our master bedroom the floor slopes a little (about 1/8 inch per foot) towards the center of the house for two to three feet and then levels off. The same is true of another bedroom on the other side of the house. The upstairs is mostly level except for these spots. The foundation seems very sturdy with no cracks from what we can tell, and the downstairs floors are level or very nearly so. The house is slab on grade.
Also in our guest bedroom I noticed that when I walk by a bookshelf (which is, admittedly, IKEA) everything on it wobbles. If I bounce in front of it the wobble is quite pronounced. Bouncing in the other rooms or bouncing in the same room near other pieces of furniture produces a tiny bit of shake (I have to bounce a lot harder to get much at all) but nothing like this one place. When you bounce you cannot hear anything significant downstairs (just sounds like footsteps).
We have not noticed any cracks except a few minor ones above baseboards and other painted wood joints (as in, they need some caulk) and near the whole house fan and sump pump hatch (which we're almost certain has to do with their installation since they are both recent). There are no cracks around doors or windows, everything shuts properly.
Any advice would be great. We are scared of big repairs so soon after buying the house.