This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
We have seen that when a dormer window is designed with two sloping roof surfaces, there is thus formed on the front of the dormer a triangular-shaped surface which must be decorated in some way and which calls for a certain amount of finish. The same thing is true of the main roof when this is designed as a gable roof, the triangular surfaces at the ends of the building being known as "gables." The problem which presents itself here is to treat the lines in which the roof surfaces meet the vertical wall surfaces at the ends of the building, and to cover up the rough timber of both the wall and the roof. The most simple way of doing this is to miter the gutters at the sides of the building at the line of the eaves with a raking molding which will follow the line of intersection between the roof surfaces and the gable wall. In the plainest work this raking molding will not project much beyond the wall line, only far enough to miter properly with the gutter. Fig. 299 shows a very simple gable end of a building with no finish except the raking molding, referred to above, mitering with the gutter at the eaves. In this figure, C is the raking molding, D is the gutter. In Fig. 300 is shown a large-scale section taken through the raking molding where marked section A-B in Fig. 299. In Fig. 300 A is the raking molding, B is the roof shingling, C is the roof boarding, D the rafters, E the end studding, F the outside boarding on the end wall of the building, and G the fascia below the raking molding. The molding is so arranged that the roof boarding stops against it and the roof shingling passes over it and projects a little beyond it so as to form a drip as shown at K in Fig. 300. In the space marked H is blocking consisting of rough pieces spaced 2 to 3 feet apart and shaped to take the back of the molding.
Fig. 300. Section through Raking Molding of Fig. 299.
Fig. 301. Common Type of Gable Finish.
There is an awkward place at the point marked E in Fig. 299, where the line of the gable meets the vertical line of the corner of the building, and some finish is usually placed here to overcome this awkwardness. In the small gable on the end of the dormer shown in Fig. 296 the fascia is carried across the face of the gable as well as along the raking line of the roof, and this arrangement is sometimes adopted on larger gable ends, but a more common practice is only to start the fascia across the gable end wall and then return it on itself a foot or two from the corner marked E in Fig. 299, stopping the raking fascia on top of it. This is shown in Fig. 301. A better result is obtained by returning the gutter molding as well as the fascia. The top of the return marked A in the figure should be sloped outward slightly so as to shed water. B and C are additional fascia boards which are added to give additional width to the raking moldings.