THATCHED ROOFS 



63 



Open Eaves. 



Fig. 64. 



In the case of open eaves the ends of the rafters are cut as shown 

 in Fig. 64, and the guttering is supported by guttering brackets screwed 

 to the rafter ends, or 

 to the lowest purlin. 



For farm buildings 

 half-round galvanised 

 iron guttering is very 

 suitable. Gutters should 

 be large, and sufficient 

 down pipes should be 

 provided to cope with 

 the torrential rains 

 common in South 

 Africa. Nothing less 

 than 4-inch half-round 

 guttering should be 



used, and 5-inch half-round guttering should be employed for larger roofs. 

 Four-inch half-round guttering should be fitted with 3-inch down-pipes, 

 while 5-inch half-round guttering should have 3^-inch down-pipes. 

 Down-pipes should not be further apart than 30 to 40 feet according 

 to the width of the roof which they serve, being closer together for 

 wider roofs. That part of the guttering which is intended to discharge 

 into a particular down-pipe should have a slope of about 1 inch in 30 

 feet towards that pipe. Thus there will be high points in the guttering 

 between adjacent down-pipes. Down-pipes may be fixed to the wall by 

 galvanised iron hooks, provided with a spike at one end, driven into the 

 mortar joints. A better method of fixing, however, is to use galvanised 

 sheet-iron bands, the ends of which are screwed to wooden plugs 

 or slips in the wall. 



Examples of the general arrangement of gutters and down-pipes 

 will be found in several drawings in this book. 



Thatched Roofs. — In thatched roofs small-sized purlins are used, and 

 in order properly to support them the rafters are spaced only 2 feet 

 apart. The purlins are 1|" by If" in cross-section, with corners 

 rounded off, and are cut from 9" by 3" deals. They are spaced 12 

 inches apart from centre to centre. To the purlins the bundles of 

 thatching grass, each bundle approximately of a size which can just 

 be spanned or ringed by both hands, are tied by tarred string about 



