[Illustration: Figure 15.--Method of flashing. Sheet metal, _h_, over the cricket, extends under the shingles _k_, at least 4 inches and is counter-flashed at _l_ in joint. Base flashings _b_, _c_, _d_, and _e_ and cap flashings _a_, _f_, and _g_ lap over the base flashings and provide watertight construction. A full bed of mortar should be provided where cap flashing is inserted in joints.] A chimney must be flashed and counter-flashed (fig. 15),[3] to make its junction with the roof watertight. When the chimney is not located on the ridge but on a sloping roof, a cricket, _j_, is built, as detailed in figure 16, high enough to shed water around the chimney. Corrosion-resistant metal, such as copper, galvanized metal, zinc, or lead, is best for the flashing and counter-flashing. When tin is used, paint it well on both sides. [3] See p. 26, Farmers' Bulletin 1751, Roof Coverings for Farm Buildings and Their Repair, for method of installing flashing. A feature, said to have originated in colonial Williamsburg as a precaution against fire hazard, is to build the upper section of outside chimneys 18 inches to 2 feet away from the gable ends of the house (fig. 17). This is not only a safety factor but a practical one because the chimney can be more easily flashed, small windows can be used in the walls of upper story rooms behind the chimney, and framing the roof is simplified. _Capping the Chimney_ 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. [Illustration: 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.