Paragraph 75. In house or roof construction the cutting of rafters is a very essential matter. In simple roof work this is not difficult. Most roofs follow the regular standards of pitch, the most common being half, third and quarter-pitch. By the pitch of the roof is meant the relation of the elevation of the roof to the width of the building. A half-pitch roof is one in which the elevation of the rafters is one-half the width of the building. To illustrate: if a building is 12 ft. wide the elevation of the rafters would be one-half of 12, which is 6 ft. To lay out the half-pitch cut a steel square should be used, as explained in Chapter 2, Paragraph 24. In cutting the brace for a door or any other purpose the half-pitch cut would be laid out in exactly the same way.

Figure 60.