CMU Spacer is a patented approach to installing concrete masonry wall systems. The spacer is a plastic molded installation tool that when coupled with a modified concrete masonry unit, enables the installation of concrete block wall systems by anyone with a basic skill set.
The tried and true method of installing concrete masonry units remains bringing together a series of concrete block with mortar made of the right ingredients and consistency by the hands of a skilled mason.
Breaking down the process of laying a concrete masonry wall into its simplest forms would be that all concrete masonry units result in face shell alignment within the wall plane using various bond patterns. The units are adhered to one another with mortar to bond the units together to become an integrated system.
The goal of the CMU Spacer is to simplify the concrete block laying process.
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. Essentially we are asking concrete masonry producers to provide units designed for installation.
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 within the work day.
Typically, concrete block are put in place all on the same course with masons laying to a string line, while using the CMU Spacers the block can be installed on multiple courses within a masons work area as they progress along the wall.
Why are trowels necessary? They are used to apply mortar to the masonry units with the appropriate volume at the edges of the block. The CMU Spacers bridge the mortar joint gap providing for the opportunity to install the mortar or the glue of the wall after the units are in place. The mortar can be pumped into place offering a higher production option.
Of course, CMU Spacers can be installed using mortar applied with a trowel just like units are currently installed.
Use of the CMU Spacers provide for weight transfer without 'crushing the joint'. By enabling the units to become weight bearing at much greater loads, construction workers are able to extend the daily height of wall attained.
In addition, productivity gains in early trials of using the CMU Spacers show that a worker can install several hundred units per day.
The masonry industry is challenged to find a solution for its future workforce. CMU Spacers provide a method to construct concrete masonry wall systems with a labor force that can be easily trained, and recruited from the pool of workers most likely to enter the construction industry.
US Patent No. 9,086,268
Concrete Block Spacer / Jones & Jones, Inc.