Section 6-101.11 - Surface Characteristics(A) Except as specified in ¶ (B) of this section, materials for indoor floor, wall, and ceiling surfaces under conditions of normal use shall be: (1) SMOOTH, durable, and EASILY CLEANABLE for areas where FOOD ESTABLISHMENT operations are conducted;(2) Closely woven and EASILY CLEANABLE carpet for carpeted areas; and(3) Nonabsorbent for areas subject to moisture such as FOOD preparation areas, walk-in refrigerators, WAREWASHING areas, toilet rooms, MOBILE FOOD ESTABLISHMENT SERVICE BASE, and areas subject to flushing or spray cleaning methods.(B)In a TEMPORARY FOOD ESTABLISHMENT:(1)If graded to drain, a floor may be concrete, machine-laid asphalt, or dirt or gravel if it is covered with mats, removable platforms, duckboards, or other APPROVED materials that are effectively treated to control dust and mud; and(2)Walls and ceilings may be constructed of a material that protects the interior from the weather and windblown dust and debris.Wis. Admin. Code Department of Health Services § 6-101.11