34 Pa. Code § 23.92 – Class II buildings.

(a) Height and location. No drycleaning or dry-dyeing buildings as enumerated in class II may exceed one story in height. Buildings may not have attics, concealed walls, concealed roof spaces, basements or pits. No building may be located within 10 feet of another building unless they are separated by an unpierced wall.
(b) Walls. No more than two sides of a drycleaning or dyeing room may have blank walls, and interior dividing partitions shall be of at least 4-hours fire-resistive construction. In addition, the walls of drycleaning, dyeing, tumbler or drying rooms shall be of one or more of the following:
1. (1) Brick laid in cement mortar.
2. (2) Reinforced concrete at least 12 inches in thickness.
3. (3) Stone laid in cement mortar at least 16 inches in thickness.
4. (4) Other noncombustible material constructed of a thickness at least 12 inches.
(c) Roof. The roof, ceiling or other construction shall be of fire-resistive construction rated 2-hours fire resistive as classified in accordance with the Standard for Fire Tests of Building Construction and Materials and listed by Underwriters’ Laboratories, Inc. Hinged skylights of metal sash and wire glass shall be placed in the roof of each drycleaning or dyeing room. They shall occupy an area equal to at least 1/8 the floor area of the room. The skylights shall be arranged to open under pressure in case of an explosion and close automatically thereafter. The roof covering shall be of incombustible material.
(d) Floors. Floors shall be constructed of concrete not less than 4 inches thick with a troweled, cement top finish and shall be of nonsparking type. Floors may not be lower than the exterior grade surrounding a wall in which there is an opening or vent. There may be no basement, cellar or open space below the floor.
(e) Egress. There shall be provided from a room used for drycleaning or dyeing two means of egress at least 3 feet in width, located as remote from each other as possible, opening directly to the outside of the building. They shall be unobstructed and ready for use at all times.
(f) Doors and windows. Doors shall be at least class A self-closing fire doors as classified by the Underwriters’ Laboratories, Inc. Every window opening shall be fitted with solid-steel sash with 1/4 inch wire glass. Doors and windows shall open outward.
(g) Intercommunicating opening. There may be no intercommunicating opening from a drycleaning, tumbler or drying room to a pressing, sewing or finishing room. There may be an intercommunicating opening between a drycleaning or dyeing room and a drying room, which shall be protected by a standard self-closing fire door rated A label or better as classified by Underwriters’ Laboratories, Inc.
(h) Sewer connection. There may be no direct sewer connection with the drycleaning, tumbler or dyeing room.