Major sinking will cause the floors upstairs to bounce
This picture is a concrete pier that has sunk and no longer supports the floor. If you were to walk above this pier you would notice a bounce in the floor that is very similar to a trampoline.
Visible moisture under the light vapor barrier
This house had the light duty 6 mil liner in the crawlspace. When you see large dark spots it is generally from water or moisture under the liner. When the ground gets really wet, the concrete will sink. When an inspector is several feet away from the concrete pier, it is never a good thing to see a large gap from pier to wooden girder. This pier is literally doing nothing to support the house.
Two sinking piers
These piers are usually around ten to twelve feet apart. This means that when two piers are are sinking it will effect more than 30 feet of your floors. You could have an entire side of your home with foundation problems from just two bad piers.
Measuring the foundation problems
DryZone inspectors measure small gaps as well as large ones. Sometimes a fish ruler comes in handy. This photo shows a huge gap between the girder and concrete pier. Seeing it from a distance is one thing but to see an actual measurement, that really puts this problem into perspective.
Wet crawlspaces lead to big foundation problems
This photo shows the general conditions in the crawlspace. Water on the ground, moisture in the air, and poor insulation are all contributing factors in foundation problems. The moisture will lead to mold and wood rot which can soften and weaken the wood. Drying out the crawlspace is always a good idea, especially if you have developed foundation problems.