[Mikendebbie]

I looked up your floor plan to see where the possible water sources for a leak are located. You did not say if the floor was rotten on one side or the other, or if it is all the way thru the basement floor. Seems to me that a leak that would rot the basement storage floor would have to be reasonably constant for quite a long time - like a leak in the convenience center would be. A leak behind the white wet bay would NOT be seen and would tend to rot the floor radiating from that corner of the basement. If the leak was from the bathroom sink or the garden tub - you would have rotten floor on the level above the basement also. Try to check out the floor below the bathroom and the garden tub. Those basement bulkhead walls are removable - so take them out and it might make it easier to chase a plumbing leak.