Counter flashing is installed over the top edge of another flashing detail. It helps stop water from getting behind the flashing, especially around chimneys and masonry transitions.
Why It Matters
Water can enter a roof system if the upper edge of flashing is exposed. Counter flashing creates a protective overlap that helps shed water outward.
Common Problems
Common issues include loose metal, cracked mortar joints, rust, gaps, sealant-only repairs, and counter flashing that does not properly overlap the base flashing below it.
Exterior Echelon Notes
Exterior Echelon treats counter flashing as a critical leak-prevention detail, especially when inspecting chimney areas and older roof penetrations.
