Shall not be assigned to a risk engaged in operations described by another classification unless the operations subject to 4036 are conducted as a separate and distinct business. Quarrying, crushing or grinding to be separately rated as 1624. Applies to manufacture of plasterboards, plaster blocks or insureds who mix plaster or staff. Contemplates the mfg. of stucco wall and roof coatings. Mfg. of cultured marble products is assigned by analogy to code 4036. Refer to code 8232 for insureds engaged in mixing and bagging concreted. Refer to code 1701 for insureds that mfg. plaster.