Chimney Flashing in San Jose, CA
San Jose Roof Repair seals the leak-prone seam where your chimney meets the roof, using fresh counter-flashing, new step flashing, and a self-adhered ice-and-water shield that keeps winter rain out of your attic. Call 6504145505 for a free roof estimate.
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Chimney flashing is the layered metal system that sheds water away from the joint where a chimney passes through the roof deck.
On most San Jose homes we deal with three pieces: step flashing laced into the staggered courses of shingles, counter-flashing bent into the masonry joint, and apron flashing at the low side.
Copper lasts longest under the intense sun we get here, though aluminum works fine when it's thick enough. We tear off the old mastic and roof cement and replace the underlayment with a self-adhered ice-and-water shield.
Then we reset the counter-flashing into a fresh mortar joint so the metal and masonry can move together without opening a gap for water to wick through.
Cost depends on chimney size, roof pitch, and access. Most single-flue jobs on a mid-century ranch or a Spanish Colonial Revival home run $450 to $1,200, and a tall two-story chase or one needing a scaffold runs more.
On flat or low-slope sections we sometimes recoat around the penetration instead of tearing into the deck. A primer system topped with a silicone, acrylic elastomeric, or polyurethane coating — products like Henry or GAF Unisil — buys years of life.
What's Included
Our Chimney Flashing Process
What Our Chimney Flashing Process Looks Like
- Roof inspection and photo documentation. We get on the roof, photograph the chimney joint from every side, and check the decking and attic for moisture before we quote anything.
- Written line-item estimate. You see the flashing, underlayment, labor, and any decking repair priced separately, not lumped into one number.
- Careful tear-off. We pull the old metal, mastic, and roof cement, then set the debris in a dumpster so your yard stays clean.
- Decking and sheathing check. Any rotted plywood, OSB, or fascia under the joint gets replaced before new flashing goes down.
- New ice-and-water shield. A self-adhered membrane runs along the uphill side of the chimney so backup water can't wick under the shingles.
- Step flashing and counter-flashing install. New copper or aluminum is laced into the staggered courses and set into a fresh mortar joint.
- Sealing and final inspection. We hand-seal the corners, set the drip edge, and walk the roof one last time before cleanup.
- Walk-through with photos. You get finished-job pictures and our workmanship guarantee in writing.
Design Consultation
On-site evaluation of placement, structural considerations, and integration with existing roof system. Manufacturer specifications reviewed.
Material Specification
Product selection matched to your building and San Jose climate. Manufacturer-certified installer crews assigned.
Certified Install
Flashing, sealing, and termination details installed per manufacturer requirements for warranty validity.
Warranty Registration
Manufacturer warranty registered in your name. Our workmanship backed by 25 warranty. Final documentation delivered.
Signs You Need Chimney Flashing
Signs Your Chimney Flashing Is Failing
- Brown water stains on the ceiling or chimney chase wall, a classic sign that water is wicking past the counter-flashing.
- Rust streaks or white mineral deposits running down the masonry after a winter rain storm.
- Visible gaps, cracked sealant, or peeling mastic where the flashing meets the chimney.
- Loose or lifted step flashing you can see has pulled away from the shingles.
- Shingle edges around the chimney that are curled, buckled, or missing granules from granule loss.
- Soft, spongy decking or a musty attic smell once the dry season ends.
- Moss or algae-stained streaks on the chimney side that stay damp long after the rain stops.
- Daylight or a draft visible around the chimney from inside the attic.
Chimney Flashing — Frequently Asked Questions
How much does chimney flashing repair cost in San Jose?
Most chimney flashing jobs run $450 to $1,200 depending on the chimney size, the roof pitch, and how much decking needs replacing. If the chase is two stories or the roof needs scaffolding, expect the higher end. We give you a written line-item estimate before we start, so the number doesn't move.
How do I know if my chimney flashing is leaking?
Watch for brown ceiling stains, rust streaks down the masonry, or a musty attic smell after winter rain. Those are the signs we see most, and they usually mean water is wicking past the counter-flashing. A quick roof inspection confirms it.
How long does chimney flashing repair take?
A straightforward single-flue job takes about half a day, weather permitting. If we find rotted sheathing or need to refit the whole flashing system, plan on a full day. We schedule around dry weather so the sealant cures properly.
Can I just seal my chimney flashing with caulk instead of replacing it?
Caulk and roof cement are temporary patches, and they're why so many chimney leaks come back. The sealant flakes and peels under our intense sun within a season or two. New metal flashing over a proper ice-and-water shield is what actually stops the leak.
Does chimney flashing repair need a permit in San Jose?
Most flashing repairs count as maintenance and don't need a permit, though a full roof replacement does. We'll tell you up front whether your job needs one and handle the paperwork if it does. Building code rules around flashing attachment are strict, and we follow them.
Will my homeowner's insurance cover chimney flashing damage?
Insurance usually covers sudden storm damage, but not wear and tear or long-term rot. We document the damage with photos and help you file an insurance claim if a covered event caused it. If it's age-related, we'll say so honestly.
Don't just take our word for it — hear from our satisfied customers.
"We had a stain spreading across the ceiling every winter, and two other roofers just wanted to sell us a full roof replacement. San Jose Roof Repair found the real problem — the counter-flashing had rusted through — and fixed just that for a fraction of the price. Honest work." — Maria G., Willow Glen
"They replaced the step flashing on our 1950s ranch and resealed the chimney in a single day. The crew was clean and polite, and they showed us photos of the rotted sheathing before they covered it back up." — Daniel R., Almaden Valley
"After the last big storm we had water coming down the inside of the chimney. They came out the next morning, replaced the apron flashing and drip edge, and it's been bone dry since. Fair estimate, no surprise charges." — Priya S., East Side
Ready to get started? Call us today at 6504145505 for a free estimate.
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