While a familiar shape, ProBlock is a totally new type of concrete masonry unit that is the lightest, best balanced, easiest and safest-to-lay block with exceptional energy performance characteristics. The ProBlock masonry wall system is a wholly new concept developed for productivity, safety, energy performance and profitability.


  • 44%+ lighter than other CMU’s making it easier to handle and quicker to install.
  • Open-end design allows masons to lay around vertical rebar and utility runs and reduce/avoid overhead lifting. Reduces rebar splicing and the amount of steel required for the project
  • Balanced center of gravity is located properly “in the center web” of the block for ease of handling.

The physical demands of block laying is not new. Since the early 1900's, the design of a concrete masonry unit has not changed. With advances in building techniques and structural stability, ProBlock allows masons to install the units in the most productive and safest way possible.

ProBlock is lighter by default due to its open end design, up to, 44% lighter in weight compared to a standard shape CMU. A lighter block is easier and quicker to install and cuts construction schedules, saves on shipping cost, and better project scheduling.
Over the course of one day, a single mason will have lifted approximately 2 tons in CMU weight, a leading contributor to back injuries and a leading cause of worker's compensation claims and missed work days. When a mason is laying between 90 to 120 blocks per day, every pound matters. Not only does ProBlock reduce the amount of weight a mason has to lift, PB allows a mason to safely lay more of them in a day.

Balanced Design - ProBlock has been engineered so that the center of gravity is where it should be; in the center web of the block. The finished result is a block that feels balanced in the hands of the mason. Most open end CMU's are imbalanced and can be troublesome to handle and even contribute to injuries, given the center of gravity is not actually located at the true "center" of the mass.

Configuration - ProBlock provides newly optimized shapes and configurations, the balanced “A” block and knock-out “H” design can be produced in full and half-high units, shapes, colors and finishes.

Open ends allow for longer vertical rebar stands. On project sites using typical block, vertical rebar pieces have to be shortened and spliced often to allow for masons to lay block over the rebar. With ProBlock's open end design, masons can more efficiently, easily, and with less effort, lay up a wall around vertical rebar in record time. Walls can be planned to include longer lengths of vertical rebar reducing the amounts of rebar splicing and the total amount of required steel.

The ProBlock innovation is more than just a new line of “A” block, but an entirely new concept concrete masonry unit. Developed by and with the mason and project in mind, ProBlock brings new efficiencies to how concrete masonry is manufactured, delivered handled and installed.

ProBlock represents a new standard starting with the development of the mix design utilizing Stalite lightweight (expanded slate) aggregate, the introduction of new (tapered) geometries to the block shape, weight and physical material distribution allowed under C-90 standards, to the “knock-out” features that delivers a highly functional, “H” shape unit.

ProBlock’s light weight design delivers increased strength, and thermal performance improvements of up to 202%+ for a typical 8x8x16 block and 254%+ for the 12x8x16 unit. Installation and handling efficiencies and mason safety advancements, along with the ability to be locally produced in a complete compliment of shapes, colors, and finishes. ProBlock supports project cost savings, improvements in the speed of construction and transportation and freight savings.

Johnson Concrete Company.
Booth N1664