Chimney flashing and cricket

Normal function

It seals the roof-to-masonry intersection while allowing water to move around the chimney instead of behind it.

What a homeowner may notice

• Rust, loose or missing counterflashing, cracked mortar joints, failed sealant, water marks on the upslope side, or no cricket where the geometry needs one.
• Leak that appears away from the chimney because water travels along framing or decking.
• Metal installed only on top of shingles without a proper layered transition.
• Masonry deterioration that can move or open the flashing.

Professional inspection

Inspect all four sides, masonry joints, the upslope diversion detail, base flashing, step flashing, counterflashing, and attic evidence. A chimney professional may be needed when masonry or flue issues are involved.

Repair or replacement path

Rebuild the flashing layers and membrane, install or correct a cricket where required by the geometry/code, repair masonry joints as a separate scope, and restore shingles with compatible materials.

Typical materials and equipment

Sheet metal, membrane, step pieces, counterflashing, compatible sealant/mortar, shingles, fasteners, and debris protection.

When to act

Active chimney leaks can damage roof deck, framing, insulation, and interior finishes; investigate promptly.

What moves the price

Chimney size/height, cricket, masonry condition, roof pitch, access, interior damage, metal type, and weather.