Sec. 791.014.  MINIMUM SPECIFICATIONS FOR INTERIOR FIRE ESCAPES.  (a)  An interior fire escape may be:
(1)  a stairway composed of iron, steel, or concrete;  or
(2)  a straight or spiral chute composed of iron or steel.
(b)  The fire escape must be enclosed with a noncombustible material.  All door and window openings in the enclosure must be protected with self-closing fireproof shutters.
(c)  Balconies or landings used with an interior fire escape must meet the construction requirements imposed under Section 791.012, except that a balcony used with an interior fire escape must permit at least 40 inches of unobstructed passageway, and the balconies or landings must be located on a level with the floors of the building.
(d)  The stairs of an interior stairway fire escape must meet the requirements imposed under Section 791.012, except that the stairs must permit at least 40 inches of unobstructed passageway in all parts.  An interior stairway fire escape may not use stairs of the types known as "spirals" or "winders".
(e)  An interior stairway fire escape must be continuous, starting at the ground floor, and may not descend to any basement.  It must extend through the roof of the building and must terminate in a penthouse constructed of noncombustible material equipped with a self-closing fire door as specified in this section.
(f)  An interior chute fire escape must meet the requirements of Section 791.013.
(g)  An interior fire escape must be accessible from all parts of the building it is designed to serve.  Each lobby, hall, or passageway that leads to a fire escape and is used in connection with it must be at least 36 inches wide and at least six feet six inches high and must be level with the floor on which the fire escape opens and which it serves.  The fire escape must be constructed at the lower end in a manner that permits direct exit to the outside of the building at the grade.
(h)  The enclosing walls of an interior fire escape may be constructed of:
(1)  brick; 
(2)  plain solid concrete; 
(3)  reinforced stone or gravel concrete; 
(4)  reinforced cinder concrete; 
(5)  hollow terra-cotta blocks; 
(6)  hollow concrete blocks composed of stone or cinder concrete mortar; 
(7)  gypsum blocks;  or
(8)  metal lath on steel studding.
(i)  If the enclosing walls are of brick or plain solid concrete, they must be at least eight inches thick for the top 30 feet, increasing four inches in thickness for each lower section of 30 feet or fraction of 30 feet, or at least eight inches thick for the entire height if the walls are wholly supported at intervals not to exceed 30 feet.  If the enclosing walls are of reinforced stone or gravel concrete, they must be at least five inches thick for the top 30 feet, increasing two inches in thickness for each lower section of 30 feet or fraction of 30 feet, or at least three inches thick for the entire height if supported at vertical intervals not to exceed 20 feet and if braced as necessary with lateral supports or suitable steel uprights.  If the enclosing walls are of reinforced cinder concrete, the concrete must be at least five inches thick for the entire height of the enclosing walls, and the walls must be supported at vertical intervals not to exceed 15 feet and must be braced as necessary with lateral supports or suitable steel uprights.
(j)  If the enclosing walls are composed of hollow terra-cotta blocks, the blocks must be laid in cement mortar, and the walls must be at least five inches thick overall.  If the enclosing walls are composed of hollow concrete blocks of either stone or cinder concrete mortar, the enclosing walls must be at least five inches thick overall.  If the walls are constructed of gypsum blocks, the blocks may be either solid or hollow but must contain not more than 25 percent by weight of cinders, asbestos fiber, wood chips, or vegetable fiber.  The gypsum blocks must be laid in gypsum plaster or cement mortar tempered with lime, and the enclosing walls must be at least five inches thick overall.  If the walls are constructed of metal lath on steel studding, they must be covered with portland cement mortar or gypsum plaster of a finished thickness of at least two inches in the case of solid partitions or of at least three inches in the case of hollow partitions.  Each opening in a wall or partition must have substantial steel framing, the vertical members of which must be securely attached to the floor construction above and below.
(k)  Each door opening in an interior fire escape must be protected by the use of an automatic or self-closing fire door of standard manufacture, bearing the Underwriters Laboratory label.  If an automatic fire door is used, it must be enclosed in a recessed partition.  All doors must be arranged and equipped to remain in closed positions at all times and under all conditions except during actual use.
(l)  Each window opening must be equipped with a metal sash bearing the Underwriters Laboratory label and with wire glass.
(m)  Each interior fire escape must be provided at each landing with at least one light equal in power to a 10-watt electric globe.  The lighting must be on a separate circuit from that of the rest of the building and must be designed to operate if the regular lighting system of the building is disabled.
Acts 1989, 71st Leg., ch. 678, Sec. 1, eff. Sept. 1, 1989.