Document 4aX5Kx7GKpnmmo4yGy8xMyX6Q

FIRE PROTECTION Pig 33-3. Exit stairway enclosures Doors on stairway enclosures at left are open, and basement fire quickly extends up stairs, spreading to upper floors Doors on stairway ot right are closed, confining fire to bosement and permitting safe use of stoirwoy Courtesy National Fire Protection Association "fire proof' is not recommended because it is misleading. No material is immune to the effects of fire of sufficient intensity and dura tion Fire-resistive construction includes walls of masonry or reinforced concrete and noncombustible framing which is ordinarily of reinforced concrete or of structural iron or steel protected by fire-resistive materials. Other structural members, such as floors, roofs, and interior partitions, that enclose stairways or other openings through floors, should also be designed to bold up for a definite period of fire resistance, adequate to eliminate structural weakening and col lapse In order to reduce the fire hazard further, nonstructural members such as par titions, acoustical and insulating materials, window tnm, window sash, shelving, lock ers, and furniture should be of noncombustible or fire-resistant materials or materials that will not contribute to the spread of fire. Although fire-resistive structures do not contribute fuel to a fire, a severe fire may occur m the combustible contents or in tenor decoration and finish materials that may more than offset the value of the nonbumable construction Therefore, restnchng the spread of fire 33-4