My house was build in 1927. I do not have standing water in my basement, but it does seem that some moisture is coming from the floor (only during a few high-humidy months in Minnesota Summer). I would like to finish the basement (it is unfinished), and would like to know of any products to use to waterproof the cement block walls (just in case), as well as the floor. It appears that the previous home-owners put something on the wall already. I will be scraping off any loose materials and power washing the entire basement. I do have a sump pump system installed around the basement . I will also be leveling off some spots, as the floor is uneven. Is this a common problem?