In basements you want to avoid flooring like carpets or hardwood because of damp. We live on a hillside with sandy soil over bedrock so there isn’t a lot of leaking likely in our house. But to be safe we went with laminate. Underneath it, we used a product called DriCore. (Click here to view) It is insulating subflooring with plastic on one side with spaces to hold air and thus, insulate but also to let water dry should some seep in. On the top is a wood subfloor which snaps together easily.
Over that we chose Roberts AirGuard insulation. It’s made of tiny balls of Styrofoam glued to a thick plastic sheeting which can be cut to fit and tapes together for a good waterproofing seal. (Click here to view)
All of these products need a level floor. For some reason the builder never put in the top coat of concrete so it was rough and tilted down in the corners and up in the centre and had enough bumps to make a phrenologist salivate. Because the former owner had painted the concrete, we couldn’t just pour over it because it wouldn’t bond. One option was to sand it off which was expensive, time-consuming and a hideous mess. The other option was to lay down a thick layer of plastic sheeting over which they could pour the few inches of concrete needed to even out the floor, so that’s what we did.