Fig. 16. Rafters and Roof Plate
The Chimney
While the chimney may be made one of the most charming and effective elements of the house design, its structural and practical necessities are its most striking features.
The proper construction, size, and height of chimneys are of the utmost importance both for the successful working of the heating system and for the prevention of fires. The chimney may, though it need not be, a point of danger to the safety of the home. A little intelligent care in its construction will prove to be the best insurance. As a first precaution, all wood framing of floor and roof must be kept at least 2 inches away from the chimney and no other woodwork of any kind be projected into the brickwork surrounding the flues.
Fig. 17. Chimney Height
Chimneys should be tightly built of solid brick, have no openings except those required for the connection of the heating apparatus, and should always extend at least one foot above the highest point of the roof. In some cases, depending on local surroundings, it may be desirable to carry them somewhat higher. Those terminating below the level of the roof usually have poor draft because the wind, sweeping across or against the roof, may form eddies that drive down the chimney or check the natural rise of the smoke ([Fig. 17]).