The spray-applied coating lasts about 10 years, while the admixture lasts for the lifetime of the block. The admixture is generally more expensive but quickly gains advantage over the sprays as the building ages. There are many local manufacturers of concrete block. See listings in this Division. Adobe is used by approximately one-fifth of the world s population to build homes and cities.
Sand is a filler while the clay and water serve as binders.
Adobe requires no mechanical energy to produce, is non-polluting, and uses locally available materials. It is labor intensive, yet forgiving in that mistakes can easily be repaired. It is a massive material that is effective at storing heat and tempering living spaces. Asphalt is sometimes added to make it more durable in transportation and less permeable to water, and Portland cement can be added to increase its structural capabilities. Adobe can be poured into forms to make bricks or puddled to create monolithic walls as the Native Americans of the Southwest did.