Chimney Flashing Repair in Fillmore: Written Report, Licensed Technicians

A homeowner on the Hampshire Road corridor called us last spring after their buyer's inspector flagged water staining on the ceiling drywall directly below the chimney. The home was a 1988 two-story stucco build, typical of the tract developments that went up across Westlake Village and Thousand Oaks central during that era. The seller had never noticed a leak because the fireplace only got used a handful of times each winter. But one heavy February rain had left a faint brown ring on the ceiling, and the buyer's inspector caught it on camera. The deal was at risk. The seller needed a clear answer fast: was this a crown problem, a liner issue, or flashing failure?

We scheduled a same-week inspection and brought a camera up for a close look at the chimney-to-roof junction. What we found was a common scenario on these late-80s homes. The original step flashing along the left rake had been face-nailed into the stucco and sealed with roofing tar, which had dried out and cracked after 35 years of Conejo Valley sun. The counter flashing above it had pulled away from the mortar joint by about a quarter inch. That gap was the entry point. The crown was actually in decent shape, and the liner showed no defects. Flashing was the sole culprit, and we could fix it within the escrow timeline.

We removed every piece of the original step flashing and counter flashing down to bare roof deck and masonry. The replacement step flashing went in with lead sheeting rather than aluminum. Aluminum corrodes when it contacts the alkaline mortar on stucco chimney chases, and that chemical reaction is one of the main reasons flashing fails early on homes in Thousand Oaks central and surrounding neighborhoods. We also installed a small cricket on the uphill side of the chimney where debris had been pooling against the back wall. That pooling accelerates rust-through on aluminum and degrades sealant joints within just a few seasons of SoCal's concentrated rainy months from December through March.

The counter flashing was set into freshly cut reglets in the mortar joints, then sealed with high-temperature polyurethane. This method meets NFPA 211 standards for chimney weatherproofing and follows the flashing integration details recommended by roofing industry authorities. We documented the full repair with photos and a written report the seller could hand directly to the buyer's inspector. Escrow closed on schedule. If you have a chimney leak or a real estate inspection deadline, call Baker Family Chimney Contractors to book your inspection.