I recently inherited my grandparents home. It is probably 65 years old with a concrete foundation and crawl space underneath. It was built on to about 45 years ago. The older part of the house has several cracks in the outside concrete foundation. I don't know if they are recent or have been there for years. I see none in the newer part of the home. Is this something to worry about? Should I fill in those cracks? Some of the cracks are a couple of inches wide.