Basement System Waterproofing - How to Find Leaks
All basement system waterproofing techniques revolve around finding the areas that leak and sealing them. In cases where you cannot identify where a leak occurs, then follow this technique. First, find the wall which you feel is allowing leakage to enter into the basement.
Then take a 12 inch square of aluminum foil to that wall and tape all four sides as tight as possible. Wait 24 to 48 hours and then take the aluminum foil off. If the side facing the wall is wet, then you have seepage in that area. Otherwise, if the side facing you is wet, then it’s just condensation and not a leak.