Almost every home that has a concrete basement faces the problem of dealing with foundation cracks at some time or another. Cracks may occur due to various problems, one of the most common being the shrinkage in volume of the concrete as it cures, causing a stress in the concrete wall. The stress is relieved on the concrete by cracking.
Shrinkage cracks can usually be found at places where there is a change in height of foundation wall such as corner of basement windows and at the centre of long walls. In spite of waterproofing, many homes are forced to deal with the problem of water seepage in their basement.
There are various reasons for this:
When the basement window corners crack, rainwater enters the crack and runs down through it till there is a narrowing of the crack. This forces the water to enter the basement wall interior face.
If you have waterproofed the walls, soil above the waterproofing allows water to penetrate the protective layer. During rains, water seeps through the top of the waterproofing layer and leaks down until it reaches the basement wall interior face. On foundation walls that are not waterproofed, water enters to the interior basement walls with ease through any shrinkage cracks.