Three coat stucco is recognized by IBC/IRC building codes and remains one of the most popular exterior cladding choices for both residential, multi-family, and commercial projects. As its name suggests, three coat stucco is applied in three layers:  3/8-inch thick scratch coat, 3/8-inch brown coat, and 1/8-inch finish coat. The approximately 7/8-inch three coat system is applied over an approved weather resistive barrier and metal lath by hand using a trowel or it may be machine applied.