When building a structure it is imperative that it's foundation be sound in order for it to withstand the tests of time and the wear and tear of the elements. Block masonry uses strong concrete blocks that not only provide exceptional stability, but typically have much lower water absorption rates than brick. This makes block ideal for building foundations. Block is also often used as the structural core for veneered brick masonry, or used alone for the walls of factories, garages and other "industrial" buildings. Concrete blocks are generally designed with "voids" in which added reinforcement such as rebar and steel can be added for increased strength.