STEEL FRAME MILL BUILDINGS. 



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Steel Frame Mill Buildings. The framework of a steel frame mill building consists of a 

 scries of tr.uisverse bents, which carry the purlins on the tops of the trusses, and girts on the 

 sides of the columns to carry the covering, Fig. 4. The framework is braced by diagonal bracing 

 in the planes of the roof and the sides of the building, and in the plane of the lower chords. A 

 transverse bent consists of a roof truss supported at the ends on columns and is braced against 

 endwise movement by means of knee braces. The framing plan for a steel frame mill building 

 is shown in Fig. 4. Steel mill buildings are also made with end trusses in place of the end framing 

 shown in Fig. 4. 



Monitor Ventilator 

 \A 



A 



S i Clerestory 



SIDE ELEVATION 



Truss-* 



END FRAMING 



f - Pur I in 



'-Truss 



.- i. Struf 



I-/ Sfrut 



.- Pur fin 



,Do 



sOo 



'Do 



&RAC1N6 A-A 



PLAN LOWER CHORD PLAN UPPER CHORD 



FIG. 4. FRAMEWORK FOR A STEEL MILL BUILDING. 



Types of Roof Trusses. Several types of roof trusses are shown in Fig. 5. These trusses 

 have been subdivided so that the purlins will come at the panel points, and will not have a spacing 

 greater than 4 ft. 9 in., the greatest spacing allowed for corrugated steel roofing when laid without 

 sheathing. The Fink trusses shown in (a) to (g) are commonly used in steel frame buildings 

 and are very economical. The other types of trusses need no explanation. 



Different methods of lighting and ventilating buildings through the roof are shown in Fig. 6. 



Saw Tooth Roofs. The common type of saw tooth roof is shown in (m) Fig. 6. The glazed 

 leg faces the north and permits only indirect light to enter the building, thus doing away with 

 the glare and varying intensity of light in buildings where direct sunlight enters. In cold climates 

 the snow drifts the gutters nearly full and causes loss of light and also leakage from the over- 

 flowing gutters. The modified saw tooth roof shown in (n) was designed by the author, to obviate 

 the defects in the common type of saw tooth roof. The modified saw tooth roof permits the 

 use of a greater span and more economical pitch than the common form shown in (m). 



Transverse Bents. A number of the common forms of transverse bents are shown in Fig. 7. 

 Transverse bents (a), (b), (d), and (A) are used for boiler houses, shops, etc., while (c), (e), (/) 



