69
3220.028
PCA Committee
Concrete Masonry Handbook
Book
Portland Cement Association
1975
April 30
31-44
N
Fire safety in buildings is a major consideration in most building codes. The governing philosophy behind various building code requirements with respect to fire is structural safety during the fire and containment of the fire. If a fire occurs, the construction should function to prevent its further spread. Thus the components of buildings must have certain degrees of resistance as barriers to the spread of fire, depending upon the nature of the occupancy, the fire zone classification, the character and concentration of combustibles, and other considerations.The fire containment philosophy is perhaps best exemplified by the provisions for fire walls. Code requirements for fire walls are considerably more rigorous than for other walls and partitions. Fire walls must not only be capable of withstanding the heat effects of the most severe fire possible under the particular occupancy but also of resisting the impact and overturning forces which may develop on either side from collapsing floors or other falling members. To ensure their lateral stability, fire walls are therefore of noncombustible construction and may be specified for a 4-hour construction rather than a bare minimum of say, a 2-hour resistance to heat transmission. Concrete masonry is particularly well suited to fire wall construction and any fire resistance up to 6 or more hours can be economically achieved.