Three types of flashing are available: sheet metals, plastics, or a combination of materials.
Not all sheet metal flashings are suitable for masonry construction. Aluminum and lead are highly susceptible to corrosion when in contact with wet mortar. They should not be used in masonry walls. Metals galvanized with zinc coatings can be used in masonry construction, but are not highly recommended. Copper, on the other hand, is an excellent flashing material for masonry. It is moderately priced, a superb moisture barrier, and resists the alkalies in fresh mortar. Stainless steel is an excellent flashing material too. It's impervious to moisture and resists chemicals well.
The most widely used plastics are polyvinyl chlorides (PVC). They are homogeneous, waterproof, impermeable sheets that remain flexible and crack free at -20 degrees Fahrenheit.
Some of the most common flashing combinations are sheet metals coated with a flexible compound. One type combines glass fiber or a cotton fabric with a bituminous compound that is bonded to a sheet of copper. Another type of flashing consists of textured, waterproofed, creped kraft paper bonded to copper or lead sheet metals with asphalt and reinforced with glass fiber. A third type of combination flashing is made of a metal foil coated with a polyester film that is reinforced with a glass fiber mesh.