Chimney Flashing Experts Since 1980's. Fully Insured.

Flashing refers to thin pieces of impervious material installed to prevent the passage of water into a structure from a joint or as part of a weather resistant barrier (WRB) system. The origin of flash and flashing are uncertain but these words are related to a pool of water and the word splash.
Counter-flashing (cover flashing, cap flashing) is when there are two parallel pieces of flashing are used together such as on a chimney where counter-flashing is built into a chimney and overlaps a replaceable piece of base flashing. Strips of lead used for flashing an edge were sometimes called an apron, the term is still used for the piece of flashing below a chimney. Flashing may be let into a groove in a wall or chimney called a reglet.