ASTM C842-05(2015) Standard Specification for Application of Interior Gypsum Plaster

ASTM C842-05(2015) Standard Specification for Application of Interior Gypsum Plaster   1.1 This specification covers the minimum requirements for full-thickness (in accordance with Table 1) interior gypsum plastering on gypsum, metal, masonry, or monolithic concrete bases designed or prepared to receive gypsum plaster. (A) Base coat plastering of the same proportions as specified for unit masonry is not prohibited from being used over plain or reinforced monolithic concrete, provided the surface is first covered with a metal plaster base or first coated with a bonding compound. (B) Finish coat plaster applied direct to a bonding compound over vertical monolithic concrete shall be not more than ³/16 in. (4.8 mm) in thickness. Where more than ³/16 in. of finish coat is required to bring such vertical surface to a true plane, a base coat of plaster shall first be applied to the bonding compound. (C) Where horizontal or vertical monolithic concrete surfaces require more than ³/8 in.