Masonry contractors use assorted types of bricks and blocks to construct foundations and walls for buildings. The light grey rectangular blocks, usually with hollow centres and dimensions of 8 x 8 inches x 16 inches, are called many names, including concrete masonry units (CMUs), masonry blocks, concrete blocks and breeze blocks. Although the names for the building blocks vary, they are normally made of the same materials and used interchangeably in construction projects.
Breeze Block History
Before the introduction of breeze blocks, builders used heavy rocks and stones for building or concrete that was reinforced with gravel or broken stone. To increase productivity and make sturdier, lighter weight structures, they sought an alternate to these aggregates. In the early part of the 20th century, Henry Page, Sr. reportedly bought a breeze block maker by mail order from Sears and Roebuck. He dug up the family's farm land in Poughkeepsie, New York and made blocks from the debris in the dirt, which included cinders, dirt and old cement fragments. The blocks he produced were used throughout the region to construct new buildings.
Characteristics and Misconceptions
Since replacing rocks and gravel with cinders made the block lighter and less dense than the earlier versions, the notion that they were inferior to heavier blocks was common. However, the strength of the blocks comes from the proportions of water, cement and aggregate as well as the production methods used. Although cinder or cement blocks manufactured early in the last century may lack the conformity of more modern ones and vary in strength, their durability cannot be determined by age alone.
Common Block Problems
When walls or foundations fail, the problems may be attributed to cracks or shrinkage of the cinder or cement blocks or in the mortar used to glue them together. Horizontal cracks significantly compromise the structural integrity while vertical cracks may be due to shrinkage and pose no serious threat of collapse. Fissures and cracks in corner blocks of structures are commonly the result of the ground beneath repeatedly freezing and thawing. The seriousness of these cracks varies and should be evaluated by a masonry professional.
Although the manufacturing of cinder or cement blocks is performed on a much larger scale than 100 years ago, cinders from coal combustion byproducts and volcanic ash are still common ingredients. Modern technology, along with construction material production standards and building codes, guarantees the uniformity and quality of concrete and breeze blocks as well as other commonly used building materials, like lumber, fasteners and metal beams and supports.