The headers are shown in section at A and B in Fig. 191, and it will be noticed that they are not used in exactly the same way. The piece at the top A is so placed that its longer dimension is at right angles to the plane of the roof, while the piece at the bot tom B has its longer dimen sion vertical. In the case shown in Fig. 1S9, where the front wall of the dormer is merely an extension of the main wall of the build ing, there is no need of the lower header B, the main wall plate taking its placE and supporting the studding for the front wall of the dormer, as shown at the right-hand side of Fig. 191.
Fig. 191 shows sections taken through two dormers of the types mentioned aboVe, parallel to the direction of the main rafters and at right angles to the main wall plate of the building. At the left is a section taken through the type of dormer shown in Fig. 1SS, while at the right a section of the other type is shown. The studs C C which form the side walls of the dormer, are notched over the trimmer rafters and roof boarding about 1 inch, and allowed to con thine downward to the attic floor. This is shown at section D D. At E is a section of the trimmer rafter, C is the wall stud, G is the attic floor boarding, and II is a section of one of the attic floor joists.
The studs C are in line with the studs forming the side walls of the attic room, so the studs I can not be carried down to the attic floor. They are stopped, at time bottom, against a 2X3 inch strip K which is nailed to the side of the trimmer rafter. At L is the ridge board, and lI III M are the short rafters which form the pitch roof of the dormer. They may be very light, as they are short and carry little weight. They rest, at the foot, on a plate 0, and at the top bear against the ridge hoard L. In the dormer shown on the right of the figure the rafters P are in planes parallel to the main rafters, and a furring piece S may be nailed to each of them so as to give the dormer roof any desired curve.
Besides the openings in the roof frame for dormer windows there must be other openings for chimneys and skylights. These are funned in the same way as explained for the dormer openings, with headers and trimmer rafters. A plan of such an opening is shown at E in the roof framing plan in Fig. 174.