Hello, I live in Canada and we had mold in the basement. We had the exterior of the house graded away from the house, and had a spray foam insulation company come by and spray foamed our basement walls. I have since finished the basement to use as a rental property. Last year, due to the gutters not being properly attached, we had some water fill up a window well during a heavy rain fall and come in through the basement window to the finished basement. This occurred in August -- our tenants have stated that they smell mold in that room now (they didn't smell anything before). Upon inspection, there is no mold on the finished drywall and I personally don't smell anything. I'm just wondering if it is possible that there could be mold behind the walls that they're smelling -- and if so, wouldn't the mold make it's way to the interior walls by now? Any help would be helpful. I know that the tenants never open the windows/blinds and kept the door closed for that specific room for awhile - so there was limited circulation.

I have a finished basement that has an internal french drain system that runs to a sump pump. Typically I don't have any issue with water if its a steady rain. But when we get a heavy rain all at once, like a storm in the summer, I get a lot of water coming into my sump. Since 2011, I have had three floods in my basement due to pump related issues. I'm trying to find a way to keep this from every happening again. One idea is to add a second sump pit with a separate pump. I would run an overflow line out of the main sump over to that one, so if there was a pump failure, the second one would be there to back it up. This would work fine, unless I were to lose power, which has never happened during a storm since I've moved in. My second idea was to dig down outside the foundation and lay in pipe which will then be tapped into the internal french drain. That would then run down grade to the end of my property. This sounds like a good idea, but i'm not sure if the water would flow from the internal french drain out into the outside pipe when under hydraulic pressure. Any thoughts?