Chimney Flashing Repair in Studio City: Written Report, Licensed Technicians

Last October, a homeowner on a hillside lot just off Coldwater Canyon called us after a small brush fire burned within 200 yards of their property line. The fire never reached the house, but the radiant heat warped the aluminum counter flashing around their two-story masonry chimney. They didn't notice right away. What got their attention was a water stain spreading across the ceiling of their living room after the first November rain. They assumed the roof was leaking. Their roofer came out, walked the roof, and told them the problem was the chimney flashing, not a roofing failure. That's when they called Estateguard Chimney Care.

This situation is common along the Mulholland Drive corridor and into the Hidden Hills border, where estate homes sit in high-severity fire zones surrounded by dry brush and chaparral. Even when a wildfire doesn't directly contact a structure, heat exposure between 400°F and 600°F is enough to cause aluminum flashing to buckle and pull away from mortar joints. On this Coldwater Canyon property, the step flashing along the roof-to-chimney junction had separated by nearly a quarter inch on the uphill side. Water was channeling behind the flashing, running down the interior wall cavity, and pooling above the drywall. The homeowner needed more than a patch. They needed a full flashing replacement with materials rated for wildfire-adjacent conditions.

Our CSIA-certified inspector ran a Level 2 inspection with a camera scan of the full flue interior and documented the exterior damage. The step flashing on the uphill slope had failed at three of eight courses. The counter flashing, which was original aluminum from the home's 1970s construction, had warped enough to create visible gaps along the reglet cuts in the mortar. We also found that the chimney cricket on the back side was undersized for the roof pitch, causing debris and water to pool against the chimney base during rain. Per NFPA 211 standards, the interior flue was still structurally sound, but the exterior envelope needed a full rebuild of the flashing system before the next rain season.

We replaced the aluminum counter flashing with lead, which handles thermal expansion and radiant heat far better than aluminum or galvanized steel. Lead flashing won't buckle at the temperatures common during nearby brush fires. We rebuilt the cricket to match the actual roof slope, adding enough height to shed water and ash debris away from the chimney base. Every step flashing piece was set into fresh mortar joints and sealed with high-temperature flashing cement. The job took a day and a half. The homeowner now has a flashing system built to survive both SoCal rain season and the next fire that moves through the hills above their property. If your chimney has been exposed to wildfire heat or you're seeing water intrusion near the chimney, book an inspection before the damage reaches your masonry structure.