CONSTRUCTION' AND FIRE TROTECTION OF COTTON WAREHOUSES. 45 



such as fre(iuontly occur in the exterior wall, which support the 

 ends of floor or roof plank, should be lightly anchored to the wall 

 by bolts for the purpose, although the bearing should be directly on 

 a lodge formed by an offset or corbel. 



Timber ends supported by posts should have a direct bearing over 

 the post and have a supplementary connection from an iron cap or 

 wood bolster such as is shown by figures 4 and 5 of Plate XXVI. 

 Where a floor is supported, the post above this floor should be tapered 

 and carried between the ends of the timbers of the floor below to a 

 firm bearing on the column bolster or cap ; the ends of the abutting 

 timbers should be beveled so as to secure a direct bearing. Such con- 

 struction is shown by Plate XXVI, figure 5. The timbers are secured 

 by lag screws connecting them to the bolster which is in turn spiked 

 to the post. This bolster is of further value in stiffening the timbers 

 against deflection under load. The iron cap of suitable desigii may 

 be used in place of the bolster. Use of the iron cap is to be preferred 

 for one-story buildings where the use of power trucks is contem- 

 plated. In such cases the post should be securely framed to reduce 

 the likelihood of its being knocked out by the truck. Posts support- 

 ing the roof should be secured to it in such manner that slight lifting 

 of the roof by wind would not allow the post to fall. The post which 

 is supported at the first floor should always rest on a cast-iron plate 

 in order that there may be no penetration of moisture from the pier 

 into the wood to cause decay, and to equalize and distribute the load 

 over sufficient area of the pier. (The pier should, of course, be of 

 substantial masonry such as was described for use under ground). 

 The lower end of this post should contain a hole about 1| inches in 

 diameter and of equivalent depth which should fit over a lug, or 

 knob, formed on the bearing- plate. This gives stability against dis- 

 placement by blows from trucking. The framing described is simple, 

 economical, and is most satisfactory in behavior when subjected to 

 fire. Timbers should be dressed on all exposed sides and have cor- 

 ners chamfered, or beveled, and splinters removed. 



For preservative and fire retardant treatment of wood, see the 

 concluding paragraphs under " Semi-slow-burning construction." 



FLOORS. 



Planking for floors above the ground and for the roof should be 

 thick. All exposed sides should be dressed and edges should be well 

 matched by being tongued and grooved or splined, preferably the 

 latter. (In splined construction the edges of the plank provide a 

 deep, wide groove into which a wooden strip is fitted tightly.) Thig 

 construction insures a close joint, Avhich prevents the ready passage 

 of flame and retards the leakage of water used in extinguishing fire. 



