Flashing Repair

Why Flashing Is the Most Common Leak Source

The field of a roof — the broad expanse of shingles, tile, or membrane — is designed to shed water by directing it downward and off the edge. The challenge is at transitions: wherever the roof surface meets a wall, a chimney, a skylight, a parapet, or a penetration. These junctions cannot simply rely on lapped materials; they require metal flashing and sealant to create a water-tight seal across a joint that moves, expands, and contracts with temperature change.

Flashing is exposed to UV radiation, thermal cycling, and wind on virtually every roof. Over time, the sealant that holds the flashing to masonry or framing cracks and separates. The metal itself can corrode, lift at the edges, or be pulled free by wind. When flashing fails, water finds a path — often running beneath the surface materials for a considerable distance before appearing as a ceiling stain inside.

Types of Flashing We Repair

• Step flashing — individual metal pieces that integrate with shingles or tile along wall-to-roof transitions, typically at dormers and additions
• Counter flashing — the upper portion of a chimney or wall flashing system that overlaps step flashing and is embedded in masonry
• Chimney flashing — the full assembly around a chimney base, including step, counter, and saddle (cricket) flashing at the upslope side
• Skylight flashing — the frame and pan flashing around skylights that directs water around the curb and onto the roof below
• Valley flashing — metal or membrane at roof valleys where two slopes meet and water concentrates
• Pipe boot and vent flashing — collars around plumbing vents, exhaust stacks, and other penetrations
• Drip edge and eave flashing — metal at the roof edges that directs water into gutters and away from fascia

Chimney Flashing — A Common Problem Area

Chimney flashing failures are among the most frequent sources of interior water damage on Livermore-area homes. Chimneys are isolated masonry structures that expand and contract independently from the roof framing around them. This differential movement gradually works the counterflashing free from the masonry mortar joints and allows water to enter behind the flashing system.

A properly executed chimney flashing repair involves correctly embedding the counterflashing in the mortar joints, installing or replacing the step flashing at the sides, and addressing the back of the chimney — where a saddle or cricket is required on wider chimneys to divert water that would otherwise pond against the masonry.

Skylight Flashing

Skylights are convenient and attractive, but they are complex penetrations that introduce multiple flashing junctions into the roof field. A leaking skylight may be failing at the head, at one of the side flashings, at the sill, or at the skylight curb itself. Not every skylight leak requires a new skylight — in many cases, the existing skylight is sound and the flashing assembly around it needs to be reworked or replaced.

Frequently Asked Questions — Flashing Repair

Related Services