Masonry Magazine May 1978 Page. 15
Flashing Projections and Recesses.
Flashing projections and recesses, with the outer edge bent down to form a drip and the back edge turned up at the inner face of the wall. (See Fig. 5.)
FLASHING
WEEP HOLES
DRIP
-FURRING
FIG. 5
Flashing Projections and Recesses.
Roof Flashing.
Because roof flashing occurs at very vulnerable points, it must be designed and installed with great care. Base-flashing design depends upon the type of roofing material. Where base-flashing is metal, the counter flashing should also be metal, extending into the wall and overlapping the base-flashing. At chimney walls, imbed counter flashings securely in mortar joints. (See Figs. 6 and 7.)
Parapet Walls.
Face both sides of parapet walls with the same durable masonry materials. Using an inferior material on the side not exposed to view is a frequent cause of future trouble. Do not paint or coat the backs of parapet walls; they must be left free to dry rapidly.
Unless coping is impervious with watertight joints, place through flashing in the mortar bed beneath it. Where the coping provides an adequate drip, the flashing may stop at the wall surface. However, where the copings are flush with the surface of the wall, extend the flashing at least 1/4 in. on both sides and turn it down to provide a drip. Follow the same procedure when topping out piers, pilasters, etc. (See Fig. 8.)
COPING
TERRA COTTA COPING
(Grout Filled)
DRIP
COUNTER
FLASHING
BASE
FLASHING
COUNTER
FLASHING
ORIP
FLASHING
BOND BREAK
-FURRING
FIG. 6
Roof Flashing.
FIG. 7
Chimney Flashing.
-FURRING
FLUE LINING
CAP
COUNTER
FLASHING
BASE
FLASHING
FIG. 8
Flashing Copings of Parapet Walls.
PLANTER BOXES
General. Planter boxes contain soil and üllers which have high percentages of soluble salts. If these boxes are not continually moistened by natural rain and snow, they are artificially moistened to assure plant growth. Hence, by their very nature, planter boxes almost always exist under conditions most conducive to stains and efflorescence; that is, the presence of soluble salts and excessive moisture. Without proper flashing, discoloration of planter boxes is almost certain to occur.
Flashing Placement.
Completely line the interiors of planters with an impervious membrane, assuring that all seams are permanently joined. Lap flashing over this membrane, extend it above the soil level about 2 or 3 in., and bend it and extend it through the planter walls. To prevent capillary moisture rise, seal seams between the flashing and the impervious membrane (which may be identical materials). This is one place where sheet metal flashings are most advantageous because they can be installed as a pre-formed, metal-pan lining.
Drainage.
Without some openings at the bottom of a planter box the soil will sour and vegetation