Portland cement stucco finishes when properly applied are durable, fire-resistant, and require little maintenance. Skilled craftsmen can produce a variety of effects in color and texture.
The usual ingredients of Portland cement stucco are Portland cement, aggregate, water, and sometimes mineral pigments for color, and plasticity materials to provide increased workability.
The aggregate should be clean fine sand, crushed stone, or crushed slag and should be free from harmful amounts of loam, silt, soluble salts, and vegetable matter. It is important that the aggregate be well-graded and have a sufficient amount of coarse particles to produce the densest possible mixture.
One of the principal causes of crazing and cracking is an excessive amount of fine material in the aggregate.