Q: Is there a difference between cast stone and precast concrete? Or, are they just two names for the same thing?

A: The most basic definition of precast concrete is concrete cast somewhere other than its final position. Cast stone falls within that broad definition, but it has a more specialized meaning. ACI defines cast stone as concrete or mortar cast into blocks or small slabs in special molds so as to resemble natural building stone.However, the Cast Stone Institute’s website refers to it as “a masonry product, used as an architectural feature, trim, ornament, or facing … [It] can be made from white and/or gray cements, manufactured or natural sands, carefully selected crushed stone, or well-graded natural gravels and mineral coloring pigments to achieve the desired color and appearance.” The biggest difference between architectural precast concrete and cast stone is that cast stone isn’t permitted to contain bugholes or air voids and must have a fine-grained texture, which is normally achieved by acid etching.