GLAZING AND PAINTING 103 



roof, the upper and lower edges of the panes 

 are sometimes dipped in a shallow tray con- 

 taining thick paint. They are laid while the 

 paint is soft, and in hardening this forms a 

 tight, waterproof joint. Zinc glazing strips, 

 bent in the form of a letter Z were at one 

 time quite extensively used between the 

 panes to make a tight joint. They are still 

 used to some extent between the panes on 

 side and end walls. 



Several advantages are claimed for butted 

 glazing: (i) Less glass is likely to be broken 

 by accidents, for if only one pane is hit, it 

 only will be broken; while if the panes are 

 lapped, the one immediately below is often 

 cracked. (2) Less glass is broken by the ac- 

 tion of frosts, as there are no laps in which 

 moisture can collect and freeze. (3) The 

 roof is lighter, as there are no laps to ob- 

 struct the sunlight. 



The chief disadvantage, aside from leak- 

 age, is the difficulty in repairing the roof 

 when a glass is broken, for the pane must 

 be cut to fit tightly. In cold, stormy 

 weather, this is a slow and tedious process. 



Butted glazing is much less used than 

 formerly among practical growers, which is 

 proof that, in general, it is not so well suited 



