Chimney Flashing Repair in Brentwood: Written Report, Licensed Technicians

After a wildfire moves through the hills above Brentwood, the damage you can see is obvious. The damage you can't see is what causes leaks for years afterward. Chimney flashing takes direct punishment during fire events: radiant heat warps aluminum counter flashing, melts roofing cement, and separates step flashing from mortar joints. Homes along the Malibu Canyon and Trancas Canyon corridors face this on a recurring cycle. Even properties that avoided flame contact often show heat-buckled lead aprons and cracked sealant lines once the first real rain arrives. According to FEMA post-fire damage assessments, chimney and roof penetration failures account for a significant share of secondary water intrusion claims in burn-adjacent zones.

The Mulholland Highway corridor presents a compounding problem. Many of these homes were built in the 1960s through 1980s with galvanized steel flashing that was already past its useful life before any fire exposure. Add thermal cycling from a nearby burn, and the metal fatigues at the bend points where step flashing tucks under shingles. Cornerstone Chimney Contractors performs post-wildfire flashing inspections that distinguish between heat damage, age-related corrosion, and crown or cap failures that can mimic flashing leaks. That distinction matters because a misdiagnosis means you pay to reseal flashing when the real entry point is a hairline crown fracture. We get it right the first time. If your chimney needs broader structural attention beyond flashing, our chimney repair services cover the full scope.

A CSIA-certified inspector doesn't just look at your flashing. They evaluate the entire chimney system against NFPA 211 standards, which means your flashing repair accounts for the condition of the crown, the mortar joints, and the cricket (or lack of one). In Brentwood, where many rooflines feature complex slopes meeting wide masonry chimneys, a properly sized cricket is the difference between water diverting around the chimney and pooling behind it every January through March. Cornerstone installs crickets with lead or copper step flashing, not the aluminum that corrodes in two to three seasons of coastal-adjacent moisture. We bend and fit each piece on site rather than relying on pre-formed sections that gap at transitions.

Our process follows a specific order. We remove the existing counter flashing by cutting the reglet line, inspect the underlying masonry for spalling or mortar erosion, and address any masonry damage before new flashing goes in. There's no point sealing metal to crumbling mortar. If we find joint deterioration, we coordinate with our chimney masonry repair team to rebuild the affected courses first. Every installation uses a two-layer system: step flashing woven with the roofing material, then counter flashing set into the mortar joint and sealed. This matches the layered waterproofing approach outlined in NRCA roofing and flashing best practices. You get a written report documenting the flashing condition, materials used, and any related findings from the NFPA 211 inspection.