Masonry Magazine February 1973 Page. 9
An Information series from National Concrete Masonry Association
Fire Safe Concrete Masonry Construction 46
Introduction
Economical construction and high fire resistance are qualities inherent in concrete masonry. In addition to their ability to resist the spread of fire for a specified period of time concrete masonry fire walls provide other desirable characteristics. They do not twist and buckle, dropping beams, floors and roofs into the interior of a building. The do not contribute to the total combustible content, thus adding to the heat and smoke. They do not depend on proper operation of sprinkler systems, which must be rigorously maintained to be effective. Finally, if subjected to fire concrete masonry walls retain substantial load-carrying capacity, and, more often than not, are capable of being repaired rather than requiring replacement.
This last consideration is particularly significant for fires in offices and factories. Aside from the loss of supplies, machinery and records of practices, prolonged delay in replacing a destroyed building can result in a permanent loss of customers who must find another source of supply. Such loss is minimized if building and business can be put back in service quickly. The demonstrated ability of concrete masonry to carry out its function after fire exposure can thus contribute to the health and survival of the business.
Design for Fire Resistance
In tall building construction it is becoming less and less possible to provide means of rapid exit for all occupants. The obvious solution is to utilize compartmentation to confine fires strictly to the parts of buildings in which they originate. Zones of safety are then provided to which occupants of a burning section may retreat.
The principle of compartmentation is also utilized in smaller buildings by fire walls. Fire walls must go through a building for its full height and width and in some cases project beyond the buildings. For example it is not uncommon in some three-story apartment buildings to see wood balconies across the front. In such buildings fire separation walls should protrude outside the building to separate the balconies, thus interrupting a path where fire may spread.
To provide areas of refuge in apartment buildings of more than 15 stories fires must be confined so strictly that each apartment must be completely self-sufficient and fire resistant. Each wing of the building must have a fire wall that isolates it from the rest of the building.