324 



FARM BUILDINGS IN SOUTH AFRICA 



weight ; 4-in. diameter at the butt end is enough. For a rough timber roof, 

 the external walls of the building should be at least 14 inches thick. For con- 

 necting the timbers, use preferably f-in. bolts, one at each joint. The timber 

 must be well seasoned ; if not, it will split and shrink and the bolts will become 

 loose. In any case, the bolts should be examined some time after the completion 



/k 0//t. Pvfi "VS/W/ 



Fig. 230. 





Fig. 231. 



of the roof, and all loose nuts tightened. In roofs of rough sheds, if the 

 thatching laths are thicker than 1^-in. diameter, say If in. to 2 in., the roof 

 trusses may be placed 3 ft. apart. 



Figs. 230 and 231 show roof trusses for thatched roofs of 16-ft. and 25-ft. 

 span respectively, the timbers being all rough natural poles, except the tie-beams. 



