On several spots, If I walk across the floor, there is excessive "shake" on other parts of the floor. For example, I'll walk across my dining room and the china cabinet which is placed againced the wall will will move (presumably up and down), enough to make noise. Same with the TV cabinet in the Family Room. But I can't ever hear the floor squeak.
My guess is that the subfoor in certain areas has pulled away from the joists causing this problem. Which is the same problem as squeaky floors, correct? Is this just an extreme example of squeaky floors without the noise?
This is a 1st floor problem only (why?) and the joists + subfloor is exposed. What should I be looking for to identify the problem from the basement? How do I fix it? Shim it or tighten it up with screws and such? There seems to be a number of solutions for squeaky floors these days... what's the best solution provided that it is indeed squeaky floors that I have? Thanks!