I own a 1922 duplex and have some moisture leaching problems in the basement after a good rainfall. I did a lot of gutter work which has improved the problem some but not quite to the extent I would like. I just found in my home inspection notes and found that the home inspector commented that I need to sand the leaching walls and reseal them to remedy the problem. Is this only a temporary fix? Has anyone sanded and sealed concrete walls before? I'm not sure what what type of sander I would need or what type of sealant I should use. Cheers!