We purchased a 3000 square foot ranch that was built in 1977. We would like to finish about 1000 sf of the basement. It has poured concrete walls and a concrete floor. Currently, we have two sump pumps, one at each corner of the house. They were put in separately and do not connect. We do not have standing water, just issues when we leave things sitting on the concrete floor. A cardboard box will result with some mold underneath. Carpet tile with a rubber backing will cause some molding, efflorescence, and lime deposits to appear. The efflorescence shows up in random spots throughout the basement whether they are covered with something or not. Sometimes the basement smells musty, and sometimes not. We run a dehumidifier.
We were looking at using a subfloor system such as DRIcore interlocking tiles or Delta - FL to lay under an interlocking floating waterproof flooring material. We purchased a few pieces of the DRIcore to test an area and after a couple of weeks, we removed the pieces and the concrete floor underneath was darker and damp.
We were thinking of having our landscaper dig down to find the exterior drainage tile at the corner of the house to verify that it exists and to see if it is clogged. But then what?
We called a waterproofing contractor and he recommended finishing the interior perimeter drain tile in the basement to connect the two sump pumps. We are waiting on his bid.
Not sure what to do first or where to spend the money. Will finishing the interior perimeter drain tile work? Shall we cross the drain tile at the center of the basement? What will this do to the structural integrity of the concrete floor? We would appreciate any advice that you all may have.