The Complete Handbook of Bricks & Concrete Blocks

Chapter 1: Understanding Bricks & Concrete Blocks

Bricks and concrete blocks are the foundation of modern masonry construction. Billions of units are produced globally each year, and they appear in nearly every built environment: residential walls, commercial facades, pavements, garden walls, industrial structures, and infrastructure. Despite their ubiquity, most people—including some who work with them regularly—treat them as interchangeable commodities. They are not. The choice between unit type, grade, and specification can determine whether a wall lasts 50 years or fails in 10, whether mortar joints remain tight or crack and leak, and whether a paved surface remains stable or heaves and breaks. Understanding what bricks and concrete blocks actually are, how they function, and why specification matters is the foundation for working with them correctly.

What Bricks and Concrete Blocks Are

A brick is a solid or cored unit of fired clay or shale, typically rectangular, used as a building material. The firing process—heating clay to temperatures between 1,800 and 2,300 degrees Fahrenheit—causes chemical transformation that gives fired brick its durability and strength. A concrete block (also called a concrete masonry unit or CMU) is a hollow or solid unit made from Portland cement, aggregates, water, and sometimes admixtures, cured at ambient temperature or in a kiln. The fundamental difference is material composition and manufacture: clay bricks are fired; concrete blocks are cast and cured.

Both products are measured and specified in standard units. In North America, a modular brick typically measures 3.625 inches wide by 2.25 inches high