We can inject air bubbles into the concrete material by using chemical admixtures, which helps prevent cracking in climates that have lots of freeze/thaw events. These small voids, which are invisible to the naked eye, allow the final product to expand and contract during these events, and minimize cracking. It’s definitely recommended in the Seattle area, especially for flatwork. Foundation contractors sometimes opt for air entrainment, and sometimes opt against it. If desired, our mix designs have approximately 5% air content.