Mill Construction De昀椀ned by C.E. Paul, 1916 The term “mill construction” as commonly “Mill-construction does not consist in dis- used is the name given to that type of posing a given quantity of materials so that building construction in which the interior the whole interior of a building becomes a framing and 昀氀oors are of timber, arranged series of wooden cells; being pervaded with in heavy solid masses, and smooth 昀氀at concealed spaces, either directly connected surfaces, so as to expose the lease number each with the other or by cracks through of corners, and to avoid concealed spaces which 昀椀re may freely pass where it cannot be which may not be reaching readily in case of reached by water.” 昀椀re. “It does not consist in an open-timber A broad interpretation of the term includes construction of 昀氀oors and roof resembling the meaning given above and adds the mill-construction, but of light and insuf昀椀cient speci昀椀cation that the building shall be so size in timber, and thin planks, without 昀椀re- constructed that 昀椀re shall pass as slowly as stops or 昀椀re-guards from 昀氀oor to 昀氀oor.” possible from one part of the structure to another. This means that each 昀氀oor should “It does not consist in connecting 昀氀oor with be separeted from all others by incombus- 昀氀oor by combustible wooden stairways tible walls or partitions, and by doors or encased in wood less than two inches thick.” hatchways which will close automatically in case of 昀椀re near them. Stairways, belt “It does not consist in putting in very numer- passages, and elevator shafts are encases, ous divisions or partitions of light wood.” or preferably located in 昀椀reproof towers. Openings in 昀氀oors for passage of belts, etc., “It does not consist in permitting the use of are either avoided or fully protected against varnish upon woodwork over which a 昀椀re will passage of 昀椀re or water. The proper instal- pass rapidly.” lation of an approved automatic sprinkler system is of great importance. Ceilings in “It does not consist in leaving windows rooms where highly in昀氀ammable stocks exposed to adjacent buildings unguarded by are kept or where hazardous processes are 昀椀re-shutters or wired glass.” followed, should be protected by the use of a 昀椀re-retartant material such as plastinging “It does not consist in leaving even the laid on wire lath or expanded metal. The best-constructed building in which dan- ceiling should follow the lines of the timbers gerous occupations are followed without without an airspace between the two automatic sprinklers, and without a complete surfaces. and adequeate equipment of pumps, pipes, - and hydrants.” What Mill Construction is Not “It follows that if plastering is to be put upon a ceilling following the line of the underside In order that all sides of the the question of the 昀氀oor and the timber, it should be plain may be presented, the following abstracts lime-mortar plastering , which is suf昀椀ciently from Report No. V, issued by the Insurance porous to permit seasoning.” Engineering Experiment Station under “All the faults above recited have been com- direction of the Boston Manufacturers mitted in buildings purporting to be of mill Mutual Fire Insurance Co., may aid in elimi- construction, and all form a part of the com- nating erroneous ideas. mon practice in ‘combustible architecture.’” INTRODUCTION 11