CONSTRUCTION" AND FIRE PROTECTION OF COTTON WAREHOUSES. 17 
eral stories high whenever possible, and for the single story plant 
which is badly congested or severely exposed. Discussion of fire- 
resistive construction is taken up first so as to treat fully such sub- 
jects as masonry and other details common to the several types of 
construction. 
DISTINCTIVE ADVANTAGES AND FEATURES. 
Essential features of fire-resistive construction are the superior 
fire-resistive nature of material used in construction of all walls, 
floors, roof, structural members and details, together with such ar- 
rangement and assembly of this material as will protect the con- 
tents of the building against fires of external origin and the spread 
of fires originating inside, and will result in minimum damage to 
the building itself. It should be noted that any type of building in 
which combustible material is stored may be subjected to the most 
severe test from internal fires. Therefore the construction of the 
building should be such as to withstand an intense and sustained 
fire and, at the same time, afford the best opportunity for use of 
fire-protective equipment. The important features of this construc- 
tion may be considered as the division fire walls, exterior walls, 
roof, floors, and openings. 
TYPES OF WALLS. 
Until comparatively recent years all walls supported their own 
weight and usually a part of the load imposed by roof and floors. 
This type of wall is known as a "bearing wall." It is the type 
generally used for the cotton warehouse, both as the division fire 
wall between compartments and as the exterior wall where this is 
of masonry. With the introduction of the steel and reinforced con- 
crete buildings there came into use two other types of wall — the 
" curtain wall " and the " panel wall." The curtain wall, which 
merely carries its own weight, is often used in commercial buildings, 
though it is seldom used in the cotton warehouse ; when it is so used, 
the same limitations fixed for the bearing wall will he found ap- 
plicable. The panel wall is especially well suited for reinforced 
concrete construction and so presents advantages for some ware- 
house designs. In the usual construction, the wall is built in panels 
formed by the structural frame, the portion inclosing any story 
being supported independently. Division fire walls and exterior 
walls, for fire-resistive construction, present somewhat different re- 
quirements and therefore are discussed separately. In both in- 
stances, thickness and other provisions stated are based on brick- 
work and refer to the usual bearing wall, while modifications of 
128983°— 19— Bull. 801—2 
