When using gravel chips, masons rinse the chips and cement with an acid bath to remove extra cement. When building walls or other areas of exposed concrete, masons sometimes make repairs once the forms are removed. They cut away bad areas or loose concrete with a hammer and chisel. Then they fill the areas with cement and smooth the surface. Once the problem areas are dry, the entire exposed surface is coated with a different cement mixture.
Masons apply the mixture with a tool or a coarse cloth.
Terrazzo workers set up frames in the same way as cement masons. Building a terrazzo requires three layers of materials. First, workers lay a solid, level concrete foundation that is three or four inches deep. Once the foundation is dry, the frames are removed. Then workers place a mixture of sandy concrete on the foundation.