Roof Flashing Leaks
in Charlotte, NC

Charlotte's climate subjects metal flashing to some of the widest seasonal temperature swings in the Southeast, with cold snaps dropping into the teens in January and rooftop surface temperatures exceeding 160°F in July, causing aluminum and galvanized steel flashing to expand and contract repeatedly until fasteners loosen and sealant joints fracture. Once the sealant cracks open, each rain event drives water directly behind the flashing and into the roof substrate below.

Many Charlotte homes built before 1980 have brick chimneys with original mortar joints that have eroded through decades of freeze-thaw cycles — even the mild freezing Charlotte experiences is enough to expand absorbed moisture in soft mortar and progressively crumble the joint. When the mortar recedes, counter-flashing that was tucked into the mortar joint loses its mechanical anchor and lifts away from the masonry, breaking the watertight seal at the most critical transition on the roof.

In cost-cutting re-roofing jobs common during Charlotte's building boom periods, some contractors applied caulk alone at chimney and dormer transitions rather than installing proper step flashing, which is a code-required mechanical barrier — not just a sealant. Caulk alone degrades within a few years under UV exposure and Charlotte's heavy annual rainfall averaging 43 inches per year, leaving the penetration entirely unprotected once it fails.