CHAPTER VII. 

 STRESSES IN SIMPLE ROOF TRUSSES. 



Loads. The stresses in roof trusses are due (i) to the dead load, 

 (2) the snow load, (3) the wind load, and (4) concentrated and moving 

 loads. The stresses due to dead, snow, wind and concentrated loads 

 will be discussed in this chapter in the order given. 



Dead Load Stresses. The dead load is made up of the weight 

 of the truss and roof covering and is usually considered as applied at 

 the panel points of the upper chord in computing stresses in roof 

 trusses. If the purlins do not come at the panel points, the upper chord 

 will have to be designed for both direct stress and stress due to flexure. 



The stresses in a Fink truss due to dead load are calculated by 

 graphic resolution in Fig. 30. 



o' 



FIG. 30. 



