94 BUILDING PROBLEMS 



CUTTING RAFTERS 



107. One half the width of a house (the distance between 

 the outside measurements of the wall plates) is called the 

 run. The height of the rafters at their highest point above 

 the wall plates is called the rise. 



A roof is J pitch when it is 1 ft. high for every 2 ft. in 

 the width of the house. 



A roof is i pitch when it is 1 ft. high for every 4 ft. in 

 the width of the house. 



A roof is | pitch when it is 2 ft. high for every 3 ft. in 

 the width of the house. 



The parts of a carpenter's square are the blade and the 

 tongue. The blade is the broad and long part. The tongue 

 is the narrow and short part. 



108. To find the length of rafters, (1) measure the width 

 of the house (distance between the outside measurements 

 of the rafter plates) ; (2) 



decide on the rise of the 



rafters ; (3) counting a foot P<*>*<f ^ 



an inch on the square, take 



J the width of the house on 



the blade; (4) take the rise RMINING THE ^ Gm OF A 



on the tongue; (5) place RAFTER 



the square with these two 



points on a straight line or the straight edge of a board and 



mark the points ; (6) then measure the distance between the 



points for the length of the rafters. 



EXAMPLE. A house 18 ft. wide is to have a roof J pitch ; that 

 is, the roof is to be 1 ft. in height for every 3 ft. in the width of the 

 house. Letting an inch on the square represent a foot, take on the 

 blade of the square J the width of the house (9 in.), on the tongue 

 take J the width of the house. 



The length of the rafter without a projection over the side of the 

 house is the distance between 9 on the blade and 6 on the tongue. 



