1 Window well drain installation - $850 - $1200 per window well; 2  External excavation and waterproofing (average cost to fix weeping tile) - $100 - $250 per linear foot influenced by excavation depth and accessibility (minimums usually apply);3  Exterior crack repair - $400 - $1400;his leak costs $150 or so to repair Below are the price ranges for basement waterproofing repairs in the Greater Toronto Area. The prices listed were obtained during meetings with clients that had obtained several estimates.