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198 rafters, etc., to the upper portion, and thus there is no loss of space. It is used largely where intermediate walls or partitions for support are available to assist in carrying the flat, and also where it is desired to get as large a room space as possible. Dormers are almost always framed, and form an important part of the construction of this kind of roof. Figs. 702 to 707 fully show the construction of this description of a roof with dormers, etc. The following are the general particulars. The bridging joists of the floor are cogged and nailed on to a rebated wall plate, or which has a fillet nailed on it. The plate to receive the lower ends of the rafters is notched and secured to the top edges of the joists as indicated, the rafters being notched into this plate as shown at Fig. 705. The curb plate is supported by the rafters, and also by the studding as shown, the latter of course tenoning into the under side of the plate. The bridging joists for the flat are out of 8-in. by 2½-in., and to produce the necessary fall the first 7 ft. is tapered from 6 in. to 8 in. (see to, Fig. 703), then the remaining 7 ft. as a firring piece 2 in. thick, increasing to 4 in. thick, nailed on as shown at B to c (Fig. 703), the drip being provided for at B. Scantlings are nailed on to the firring described, forming the joists on which to nail the boarding for the flat. This boarding should be 1⅛ in. thick, grooved and tongued, and cleaned off smooth to receive the lead. The boarding should always be fixed running parallel with the fall of the flat, so that in the event of any of the boards curling up and thus forming hollows in the lead, the rain will not be retained in puddles, as its flow is not interfered with. Grooved and tongued l⅛-in. boarding is nailed diagonally on the rafters to receive the lead, as shown at Fig. 704. The curb plate having to span 8 ft. over the dormer, it is strengthened by a 6-in. by 4½-in. lintel bolted to its under side and supported by the angle studs, as indicated at Fig. 704. The front elevation and side elevation of the completed Venetian dormer window are shown at Figs. 706 and 707. The ceiling of this is arched; the ribs to carry this and the boarding are shown at Fig. 704. The framework to receive the completed window is fully shown at Fig. 704. The junction between the side and flat is finished with an upper fascia and a lower fascia, and soffit boards, moulded modillions, guttering, etc., as shown in elevation and section (Figs. 706 and 707). The construction of the dormer frame, casements, etc., will be treated of in a subsequent chapter, where a number of detail illustrations will be given.