This system is a cavity wall consisting of an exterior concrete masonry veneer and a structural CMU backup. The two wythes are anchored with horizontal joint reinforcement.. The joint reinforcement can be ladder tri-rod type, tab type, or adjustable. To resist shrinkage of the concrete masonry veneer, the selection of joint reinforcement should take into account the requirements for shrinkage control in the veneer. Control joints should be placed in this concrete masonry veneer at the proper spacing and in the proper locations. (click here for more info on control joints). These exterior units should be integrally water repellent treated and / or coated with a water repellent paint or clear treatment after construction. 

Like any other cavity wall system (click here for more information on cavity wall designs) flashing details and weep holes are critical.