TYPE OF ROOF 115 
a greater amount and better distribution of sunlight. All the roof 
water is carried to the rear; this does away with half the amount of 
eave troughs required on a two-pitch roof, and keeps the front of 
the house dry and clean. A shed-roof house is also much cooler 
in summer; the slope of the roof, being toward the north, does not 
receive the vertical rays of the sun. The shed roof is well adapted 
to any house twenty feet or less in width. The greater width is 
most economical. In such construction a central girder or purlin 
should reach the entire length of the house, with posts every ten 
feet, to support the roof (Fig. 73). 
A gable roof provides garret space, which can be stuffed with 
straw to make the house dryer and warmer; but it increases the 
amount of labor and offers a hiding place for mites and parasites. 
Fic. 73.—A well-framed poultry house. 
The combination or two-thirds span roof is often used, where 
it is desired to have an alley in the back of the house, as ‘more 
head room can be obtained in the back portion of the house with- 
out having excessive height in front. This type requires more 
labor to build, as there is much more fitting and sawing to be done. 
For houses greater than twenty feet in width, the half-monitor 
type of roof is the most desirable, and especially where it is neces- 
sary to have a central work alley with pens on both sides. The 
upper window allows the sun to penetrate to the back half of the 
house and gives an abundance of ventilation. This type of house 
is apt to be cold in the winter, as the warm air rises and comes in 
contact with the cold glass in the peak and cools rapidly. This 
can be partially counteracted by stretching muslin over the inside 
of the sash to keep the warm air from circulating directly against 
the glass. , 
The A-roof is a very economical method of covering a. given 
