Chimney Flashing Repair

Flashing is the metal, usually aluminum or copper, that wraps the base of the chimney where it passes through the roofline. It's built in layers, step flashing tucked under each course of shingles and a counter-flashing set into the masonry above it, so the two shed water past each other instead of letting it pool at the joint. On a lot of older Greenwich-area colonials and stone homes, that flashing has been through decades of freeze-thaw cycles and coastal storms, and metal fatigues, mortar around the counter-flashing crumbles, and seams that were once tight start to gap.

A flashing leak rarely looks like a leak at first. It usually shows up as a brown stain on a ceiling near the chimney, a damp patch in the attic insulation, or peeling paint on an interior wall that backs up to the chase. By the time water is visibly dripping, it's often been getting in for a while, running down the chimney's exterior or into the wall cavity rather than straight through the roof deck. That slow, hidden path is what makes flashing damage so easy to blame on the roof itself when the chimney is the actual source.

Repair depends on what's actually failed. Small gaps or lifted edges can sometimes be resealed with proper roofing cement or a new bead of sealant at the counter-flashing. Rusted, corroded, or physically damaged flashing needs to be replaced outright, tucked back under the shingles correctly and set into a fresh reglet cut in the mortar joint above it rather than simply caulked over the top. A quick caulk job is a common shortcut that fails within a season or two in our climate.

Flashing problems often surface during a full chimney inspection, especially when a homeowner calls about a ceiling stain and the actual cause turns out to be at the roofline rather than inside the flue. It's also common to handle flashing at the same time as other chimney repair work, since a crumbling mortar joint around the counter-flashing is often part of a bigger repointing need. If you're not sure where a leak is actually coming from, our chimney service in Greenwich starts with tracking down the real source before anyone climbs onto the roof to fix it.