Lots of Seattle homes have cracked foundations, especially the older homes, many of which are 100 years old or more. For many of those homes, these cracks are not a serious problem. The cause of the cracks is usually a combination of poor quality, unreinforced concrete, along with soil that was not adequately prepared to support the weight of the foundation. Often the cracks I might observe are nearly as old as those foundations.
In this instance, it is the sloping terrain that causes the problem. And also in this case, some shoring up of the foundation is prudent. The soil this home sits on is gradually moving down the hill, and cracks like the one shown here develop and widen. There are a number of possible fixes that will stabilize the foundation, including retaining walls, or retrofitted pipe piles to prevent further damage. In this case, we determined that the most economical solution was installation of piles.