Chimney Flashing Repair in Pasadena: Written Report, Licensed Technicians

A straightforward chimney flashing repair in the Arcadia and Monrovia foothills typically runs between $450 and $1,200, depending on whether you need step flashing replaced on one side or a full counter flashing reset around the entire chimney-to-roof junction. Most homes in these neighborhoods were built between the 1950s and 1980s with aluminum flashing. That aluminum has spent decades expanding and contracting through hot San Gabriel Valley summers, and the sealant has long since cracked. If your chimney also needs a cricket installed on the uphill slope to divert rainwater, add $300 to $600 to that range. We quote the exact scope after a visual inspection, not over the phone with a guess.

Here's where air quality compliance and smoke chamber condition change the conversation. If flashing has leaked for more than a season, moisture often reaches the smoke chamber walls. Damp smoke chambers collect creosote faster, burn less efficiently, and push more particulates into your living space. In the South Coast Air Quality Management District, that matters. We inspect the smoke chamber during every flashing job. If we find moisture damage or second-degree creosote buildup inside, we recommend a parge coat or chamber repair before sealing the roof line. Fixing flashing without addressing the chamber underneath is like patching a tire with a bent rim. Homeowners in Duarte and Monrovia who use their fireplaces even 15 to 20 times a season should expect this combined scope about one in every three jobs.

We start with a water test, not assumptions. A technician runs a controlled stream along the chimney-to-roof intersection while a second person watches inside the attic and firebox for moisture entry. This tells us whether the leak originates at the flashing, the crown, or the mortar joints - three problems that produce identical ceiling stains. Once we confirm flashing is the source, we remove the old material completely. In Arcadia, we frequently pull out original aluminum step flashing that's corroded through at the bend points. For replacements, we use lead-coated copper or galvanized steel step flashing pieces woven between each shingle course. Lead-coated copper costs more upfront but resists the thermal cycling that destroys aluminum in inland valleys where summer roof temperatures regularly hit 150°F.

Counter flashing gets embedded into the mortar joints using a diamond blade cut, then sealed with high-temperature urethane caulk. We don't surface-mount counter flashing with roof cement and call it done - that's a two-year patch, not a repair. If the uphill roof slope sends water directly into the chimney base, we fabricate and install a cricket from matching roofing material. The cricket diverts water around the chimney instead of pooling against it during January and February storms. After the flashing is set, we do a final water test and photograph every detail for your records. Homeowners in Monrovia and Duarte with tile roofs get a slightly modified process since the step flashing must integrate with barrel or flat tile profiles without cracking them. The full job takes four to six hours for most single-chimney homes and includes a written warranty on materials and labor.