The CMU Spacer was developed to bridge the gap of the mortar joint. In addition to bridging the gap, the spacer is designed to align and interlock.
To accomplish the functional performance of creating a space for the mortar joint, alignment, and interlock of adjacent units, the standard concrete masonry units must be equipped with channels within the face shell on the proverbial top and bottom of the units to receive the spacers. CMU Spacers used with the prepared concrete block enable the block to be installed on multiple courses along the wall, dry-stacking for placement of mortar after the block are in place, and at greater vertical heights.
Concrete Block Spacer / Jones & Jones, Inc.