Every basement problem we get called back to look at, mould, cupped flooring, ruined drywall, comes down to the same thing. Water got in after the room was finished.
Find out where the water comes from
There are three common sources and they need different fixes. Surface water from poor grading or blocked gutters is the easiest and cheapest to solve. Hydrostatic pressure pushing groundwater through the slab or wall joint needs interior drainage and a sump. Condensation on cold surfaces in humid months needs ventilation and dehumidification rather than drainage.
Start outside
Before anyone proposes interior work, check that the ground slopes away from the house, the gutters are clear, and downspouts discharge well away from the foundation. A surprising number of damp basements are solved at this stage for very little money.
Then deal with the interior
Where water is still coming through, an interior drainage channel at the wall and floor joint feeding a sump pump with a sealed lid is the standard solution. Seal any cracks properly rather than skimming over them, and fit a battery backup on the sump if the basement is going to hold anything you care about.
Control humidity
Indiana summers are humid, and a below-grade room will hold that moisture. A dedicated dehumidifier draining to the sump keeps relative humidity in a sensible range year round.
Then, and only then, finish
Once the space has stayed dry through a wet season, framing can start. We would always rather tell a homeowner their basement needs drainage work first than build a beautiful room on top of a problem that has not gone away.
