MILL CONSTRUCTION BUILDINGS 



These three general types of framing may be classed as 

 follows : 



1 . Floors of heavy plank laid flat upon large girders 

 which are spaced from 8 to 1 1 feet on centers. These 

 girders are supported by wood posts or columns spaced 

 from 16 to 25 feet apart. This type is often referred to 

 as "Standard Mill Construction." 



2. Floors of heavy plank laid on edge and supported 

 by girders which are spaced from 12 to 18 feet on cen- 

 ters. These girders are supported by wood posts or col- 

 umns spaced 1 6 feet or over apart, depending upon the 

 design of the structure. This type is called "Mill Con- 

 struction with Laminated Floors." 



3. Floors of heavy plank laid flat upon large beams 

 which are spaced from 4 to 1 feet on centers and sup- 

 ported by girders spaced as far apart as the loading will 

 allow. These girders are carried by wood posts or col- 

 umns located as far apart as consistent with the general 

 design of the building. A spacing of from 20 to 25 feet 

 is not uncommon for columns in this class of framing 

 where the loading is not excessive. This type is more 

 generally known as "Semi-Mill Construction." 



Each of these types is provided with a lighter top-floor to 

 take the wear and give a finished surface. Construction details 

 will be given in the chapters which follow. 



What Mill In order that all sides of the question may be 

 Construction presented, the following abstracts from Report 

 Is Not No. V, issued by the Insurance Engineering 



Experiment Station under direction of the Bos- 

 ton Manufacturers Mutual Fire Insurance Co., may aid in 

 eliminating erroneous ideas. 



"Mill-construction does not consist in disposing a given quantity of 

 materials so that the whole interior of a building becomes a series of wooden 

 cells; being pervaded with concealed spaces, either directly connected eacli 

 with the other or by cracks through which fire may freely pass where it 

 cannot be reached by water. 



"It does not consist in an open-timber construction of floors and roof 

 resembling mill-construction, but of light and insufficient size in timber, and 

 thin planks, without fire-steps or fire-guards from floor to floor. 



"It does not consist in connecting floor with floor by combustible wooden 

 stairways encased in wood less than two inches thick. 



"It does not consist in putting in very numerous divisions or partitions 

 of light wood." 



"It does not consist in permitting the use of varnish upon woodwork 

 over which a fire will pass rapidly. 



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