Differing from clay bricks, concrete bricks continue to gain strength with age, and have a higher sound reduction index.
Concrete bricks are produced to finer tolerances than clay bricks, providing more accuracy in block sizes. You’ll find all Marshalls bricks are produced and certified to D1 category (+3-5mm in all dimensions).
Our bricks have minimal soluble salts content, and the admixtures used both within the mix and on the surface of certain facing bricks ensure that bricks have minimal efflorescence. By contrast clay bricks may contain metallic salts such as sodium, potassium and magnesium, and consequently are categorised as either SO, S1 or S2. These define the maximum level of soluble salts
