While in a crawl space recently I couldn't help but notice a poorly-founded beam. This is the main support beam under the center of the original portion of a country home with numerous additions.
The beam has moved as the makeshift columns underneath have moved. This is very poorly done. This has likely been shifting downward from day one.
Beam support is crucial to the entire structure of any house. This is a "built-up beam," composed of three 2x10" planks that are only nailed together.
Not only is the beam not supported well, but it is also not sufficiently sized for what it is asked to do. And the planks are merely nailed together, with no support under the splices.
This beam should have been larger and made more solid with numerous through bolts in addition to properly-spaced and founded columns underneath.
How do I know it has moved?
These are just two of many photos I could have taken of the wall above that beam. The gap of the settling kitchen floor on the left is 1 1/2" and the gap of the living room floor on the right is 1". That gap varied all along that same contiguous wall. And walking along the wall created quite a bounce!
My recommendation: Transference of load onto proper support is what makes a house stand for a long time. Start at the bottom and work upward to see if support is large enough and properly positioned.
You can beam me UP now, Scottie.