CONSTRUCTION AND FIRE PROTECTION OF COTTON WAREHOUSES. 55 



knots and cross grain less objectionable than for iiio^t purposes. 

 Square edge plank free from wanes (bark or splintered corners) 

 should be insisted upon. 



Wall siding and other planking which will be exposed to the 

 weather or will be in contact with the earth preferably should be 

 heart material, but, if it is to be kept well painted or is to be treated 

 thoroughly with a preservative preparation, sap lumber may be used. 



Wood for fire-door cores — ^the door designed to ]je covered, with 

 tin — should be nonresinous or nearly so ; white pine or cypress is the 

 best material. 



Paving blocks of wood are excellent for the compress compartment 

 floor. It is desirable that these blocks be set with a pitch cement and 

 be laid over a 3-inch rough slab of concrete. 



The tendency of wood to decay should be checked by either pre- 

 ventive methods or preservative treatment or both. Deca}^ of wood 

 is caused hj a fungus which, under moist conditions or through lack 

 of ventilation or infection, aifects the Avood with alarming rapidity. 

 This growth not onlj causes rapid deterioration in timbers infected, 

 but spreads to other timbers in the building or in the lumber yard. 



From the present knowledge of the subject it appears that the 

 occasional buyer of lumber may find his best protection in a thorough 

 air drying of lumber as it is received. Timbers showing any indi- 

 cation of white mold, which indicates the presence of the fungi, 

 should be isolated. If the presence of " dry rot " is suspected, as soon 

 as the building is sufficiently complete it should be heated to a temper- 

 ature of 115° F. and held at this temperature for at least one hour.^ 



The firedoor core, or the wooden door proper which is covered with 

 tin, is subject to dry rot, as the absence of adequate ventilation con- 

 tributes largely to growth of the fungi. The heat treatment de- 

 scribed is essential to the life of wood so to be used. The heating 



^After heating, the buikling should be thoroughly ventilated and the process 

 preferably should be repeated for four consecutive days. If sprinkler equip- 

 ment is provided it should be operative while the heating is in progress, care 

 being exercised not to raise the temperature within 50° of the sprinkler 

 heiid fusing temperature. In the usual case of warehouses not designed to 

 be heated, the heat may be supplied by small stoves located on the ground 

 floor with flues carried out through ventilator collars or openings. If the 

 building is several stories in height, the plank for tlie upper flo<n-s .should 

 be laid loosely with 2-inch strips interposed between them and the support- 

 ing floor timbers while the heating is in process. (Of course, this requires 

 the cooperation of the sprinkler contractor.) Thermometers should be dis- 

 tributed properlj^ and carefully read, for luider such conditions there will 

 be considerable leakage of air and a wide range of difference in temperature 

 at and far above the first floor. ■ It is apparent that extreme care must 

 be exwcised to prevent setting fire to the building. The unfinished building and 

 materials should be insiired and a representative of the insurance interest 

 should be present while the heating is in process. 



