Failing supports
Weak and crumbling wood "support post"
Warped wood
Moist wood becomes soft and can meld into other wood, also notice the splintering of the other joist in this photo. Floor above likely to feel soft, Warped, squeaky and sagging
Makeshift wooden support
This homeowner had been experiencing sagging floors above and tried to build a wooden frame to fix it themselves. Not only is this not stable or properly installed, because they never addressed the real problem of high humidity these supports also started to rot and get weak and also failed.
Photo from inspection
No insulation in the floor joists results in freezing floors above. No insulation around the walls could cause frozen pipes in the winter.
Rim joist insulation
Making sure every seam and crack has been filled and properly insulated
Support Jacks
Supplemental beams help take the weight of the home off the soft failing wood and gives the home a sturdy and stable base to rest on.