Good and Poor Shingling 



167 



next course will come. When the courses above 

 are laid upon the shingle having but one nail, 

 two or three other nails, which are driven in 

 the courses above, will serve to help hold it in 

 position. The joints of shingle roofs should be 

 double broken: that is, the joints in the shingles 



5inple hrta.k 



• I 



X)ou,tle brtcuks 



of one course should not coincide with the joints 

 of the first or second course below. Consult 

 Fig. 77. 



If two nails be driven in the sides of an un- 

 seasoned shingle, when it shrinks it is likely to 

 split in the middle ; and in laying a roof the 

 joint immediately above the course under con- 

 sideration is likely to come at or near the mid- 



