First, foundation waterproofing is a bit of a misnomer. The truth is, nothing is waterproof. In fact everything contains water.

So, when it comes to keeping a basement relatively dry, knowing the lay of the land, type of soil or bedrock, or well springs, whether or not there is gravity drainage, how the foundation was constructed including the footing, how the drain tile was installed, the condition of the foundation wall, its age, method of construction, and a host of other variables all have a role to play.

Recently, extreme weather events also change the condition of the soil to either extreme wet or dry. When the ground is dry, it tends to become hard and compacted. Then, when there is a heavy downpour, the water tends to run off rather than be absorbed by the dry hard ground. Surface water, then, should be channeled away from any foundation before it gets there to minimize the amount of water reaching your drain tile.