Various methods of terminating chimneys are shown in figures [11] and [18]. Whatever one is used should be architecturally acceptable, effective in preventing disintegration, and so made as to keep water out of the flue.
Figure 16.—Cricket, j, as seen from the back of the chimney shown in [figure 15]. A section through the cricket is also shown. Note how counter-flashing is built into the mortar joint at l.
It is advisable to project the flue lining 4 inches above the cap or top course of brick and surround it with at least 2 inches of cement mortar finished with a straight or concave slope to direct air currents upward at the top of the flue; the sloped mortar also serves to drain water from the top of the chimney. (See [fig. 11].) Hoods are commonly used to keep rain out of a chimney ([fig. 18, A and B]). The area of the hood openings should be at least equal to the area of the flue and each flue should have a separate hood. Concrete and brick caps are usually made 4 inches thick, and it is advisable to project them an inch or two to form a drip ledge.
Many of the chimneys built today are unsightly and frequently detract from an otherwise well-designed house. Within the last 100 years the size and attractiveness of chimneys ordinarily built has declined. The large old chimneys of colonial days were proportioned to suit the house and surroundings and at the same time provide for two or more large fireplaces. With reduction in the size of fireplaces and the substitution of several stoves and eventually one central heating plant, the chimney has developed into a merely utilitarian shaft.
Figure 17.—A house in southern Maryland in which the space between the chimney and the house wall shows clearly. The practice of building the chimney in this way is common in the tidewater section of the South.