Masonry Magazine December 1996 Page. 26
FLASHING...
Tying the loose ends
by Jason Yana
The main issue when designing a quality wall system is controlling water that penetrates the wall system
The arrow indicates a properly installed, exposed metal drip, hardly noticeable from a few feet away.
Masonry has proven itself to be one of the most durable building materials available. Three common types of masonry wall systems are cavity walls, veneer walls, and composite (barrier) walls. The main issue when designing a quality wall system is controlling water that penetrates the wall system. A successful system uses flashing to perform two functions: to prevent water penetration at copings and below openings, and to direct any water that has penetrated the wall back to the outside above openings and at the wall base. The flashing strategies herein are tried and true techniques which can help create a long lasting, durable masonry wall system.
Methods of installation
The proper detailing and installation of flashing is critical. A masonry wall's longevity can be drastically compromised if standard methods and procedures are not applied. Unconventional flashing methods, teamed with a designer's oversight, can produce detrimental results, such as: efflorescence, mortar deterioration, spalling brick, excessive wall movement and interior moisture damage.
Locations
After a complete examination of the wall system, a designer might consider flashing in numerous areas. Five of the most common areas are:
1. Above wall openings.
2. Below wall openings. (window sills, etc)
3. On shelf angles.
4. At the wall base, or where the wall structure rests upon the foundation.
5. At the top of the wall / parapet.