Poor grading outside your home: This is something that is commonly overlooked because unless you are looking for it you will not see it as a problem. The grading around your home needs to have a positive pitch away from the home to allow water to run off away from the foundation. If left untreated, the poor grade towards your home will let water sit in the valley it has created and leave it nowhere to go and it will eventually seep into the ground and cause static pressure with freezing and thawing to push on your foundation wall. The water that is draining down alongside your foundation will eventually start to wick into the walls of your structure and cause staining and mold that can be toxic.