16 BULLETIlSr 801^ U. S. DEPAJRTMENT OF AGRICULTUEE. 



type which may be called semi slow-burning (or "wood-end") con- 

 struction. In addition to these, there is the less desirable frame and 

 '' iron clad " construction.^ 



FIRE-RESISTIVE CONSTRUCTION. 



Fire-resistive — sometimes called " fireproof " — construction for 

 the warehouse ranks first both in protection against fire and in low 

 cost of maintenance and depreciation charges. However, the first 

 cost is more than that for the other types of construction. For this 

 reason it is not to be preferred usually tO' the best design of slow- 

 burning construction, for single story warehouses. On the other 

 hand, fire-resisti^^e construction should be used for warehouses sev- 



1 The adaptation of the compartment to withstand fire and admit of effective 

 use of fire protective equipment is of great importance. The features of con- 

 struction will be discussed under that heading, but it may be stated here that 

 effective use of hose streams demands that the length of the compartment, or 

 the distance betvreen exterior walls, usually should not exceed 100 feet. Ex- 

 ceptions to this rule are the cases of fire-resistive construction where there is 

 but one story with large skylights through which streams of water may be 

 thrown to the center of the building, and where the construction is fire-resistive, 

 of several stories and fully protected by sprinkler equipment. In the latter 

 case the increased length of the compartment would be desirable in order .to 

 reduce tlie cost of the platforms. In this case the compartment length (be- 

 tween exterior walls) should not exceed 150 feet. 



Compartments may be combined horizontally in considerable numbers, the 

 only limitation being that single combinations constituting one building should 

 not be so long that in case of fire it would require an unreasonably long time 

 for a fireman or other person to pass around the building from one side to the 

 other. Usually the building should not exceed 700 feet in length, and there 

 should be an open space between the ends of these buildings of at least 50 feet, 

 unless the exterior walls are of substantial masonry, in which case a 25-foot 

 space is sufficient. 



The whole consideration of size of compartments is, of course, an effort to re- 

 strict fire damage. Any definite limit is necessarily arbitrary. The limit of 13 

 feet in story height is well adapted to the storage of flat cotton two bales high 

 on end or one tier on end and two tiers flat, and is a suitable proportion where 

 bales are stored entirely on the side as is frequently the case for compressed 

 cotton, bales in this position are piled five high. In this latter case additional 

 story height results in less effective use of automatic sprinkler (see section on 

 fire protection), and other fire-extinguishing equipment to such an extent that 

 the maximum should not exceed 18 feet. There should also be taken into ac- 

 count the fact that usually with the increased height, additional cotton is sub- 

 jected to fire. As previously stated, the -best distance between exterior walls is 

 100 feet and this should not be exceeded except under conditions similar to 

 those explained, and in no usual case should the distance exceed 200 feet. The 

 remaining dimension for the compartment — the distance between division walls — 

 may be adjusted entirely in reference to the value of cotton thus subjected to 

 a single possible fire. Preferably this dimension should be such as to limit the 

 volume of the compartment to 72,000 cubic feet. 



