9 CFR 354.222 - Floors, walls, ceilings, etc.
(a) Floors. All floors in rooms where exposed products are prepared or handled shall be constructed of or finished with materials impervious to moisture, so they can be readily and thoroughly cleaned. The floors in killing, ice cooling, ice packing, eviscerating, cooking, boning, and cannery rooms shall be graded for complete runoff with no standing water.
(b) Walls, posts, partitions, doors. All walls, posts, partitions, and doors in rooms where exposed products are prepared or handled shall be smooth and constructed of materials impervious to moisture to a height of 6 feet above the floor to enable thorough cleaning. All surfaces above this height must be smooth and finished with moisture-resistant material.
(c) Ceilings. Ceilings must be moisture-resistant in rooms where exposed products are prepared or handled, and finished and sealed to prevent collection of dirt or dust that might sift through flooring above or fall from collecting surfaces on equipment or exposed product.