The cost of basement waterproofing in Toronto depends on a variety of factors such as the size of the basement, the extent of the water damage, the type of waterproofing method chosen, and the contractor’s experience. On average, basement waterproofing costs range from $1,500 to $4,000. However, this cost can be as high as $10,000 or more for a large basement. Exterior waterproofing tends to be more expensive, ranging from $12,000 to $20,000, while interior waterproofing costs typically range from $3,000 to $8,000.