Renton homes built before the 1980s in neighborhoods like Kennydale and Talbot Hill often have masonry chimneys with original step flashing that has corroded after decades of exposure. The mild oceanic climate brings repeated freeze-thaw cycles and heavy winter rain that drives water under loose flashing and into the roof deck near the Renton Boeing Plant area. Proper repair requires removing the first course of shingles, installing new 26-gauge galvanized or copper step flashing, and integrating it with existing counter flashing without disturbing the chimney crown.
Edge cases appear frequently on sloped lots in the Highlands and Benson Hill where runoff concentrates at the chimney base. Homeowners sometimes attempt sealant-only fixes that fail within one season because the underlying flashing has already separated from the brick. We always check for rotted sheathing and compromised underlayment during these repairs, especially on homes near Lake Washington where humidity accelerates wood decay.
King County permitting rules require that any work altering the weather barrier on a roof must maintain the original fire rating at the chimney penetration. We use lead or copper flashing compatible with both brick and asphalt shingles common in Downtown Renton and avoid mixing metals that cause galvanic corrosion. Homeowners in nearby Bellevue and Tukwila often call after noticing interior stains during the first prolonged winter storm.
Technician insight
In Renton the thing that catches most people out with Chimney Flashing Repair is how quickly water finds its way behind corroded step flashing on pre-1970s homes in Kennydale once the winter rains start. The combination of older brick chimneys and the constant moisture from Lake Washington means sealant patches almost never hold. We always pull at least one row of shingles to check the deck because rot often extends farther than the visible stain suggests.
Kennydale Chimney Leak After Heavy Rain
A homeowner in Kennydale noticed water stains on the ceiling near the fireplace after several days of steady rain. We found the original galvanized step flashing had rusted through where it met the brick. We replaced the flashing with copper, repaired a small section of decking, and integrated new shingles so the repair matched the rest of the roof.
Chimney Flashing Repair Services We Offer
✓Step Flashing Replacement
Remove failed step flashing and install new corrosion-resistant flashing integrated with existing shingles to prevent water entry at the chimney.
✓Counter Flashing Repair
Re-secure or replace counter flashing set into chimney mortar joints so water cannot migrate behind the step flashing during heavy Renton rains.
✓Chimney Cricket Installation
Add a cricket on the uphill side of wide chimneys common in older Benson Hill homes to divert water and reduce leak risk at the flashing line.
✓Leak Detection and Dye Testing
Perform targeted water testing around the chimney to locate active leak paths before any flashing work begins.
✓Flashing and Shingle Integration
Re-lay shingles around the chimney with proper overlap and new flashing so the repair blends with the existing roof in neighborhoods like Kennydale.
Chimney Flashing Repair Cost in Renton, WA
| Service | Typical Range | What Affects It |
|---|---|---|
| Basic Step Flashing Repair | $450–$850 | Single-story homes with easy roof access; price rises with steep pitches in the Highlands. |
| Full Chimney Flashing Replacement | $950–$1,800 | Includes new step and counter flashing plus cricket if needed on wider chimneys. |
| Flashing Repair Plus Deck Repair | $1,200–$2,400 | When rotted sheathing is found near the chimney base on older Talbot Hill homes. |
| Emergency Leak Stop | $350–$650 | Temporary tarping and sealant during winter storms before permanent repair. |
Ranges are typical for Renton, WA and confirmed with an exact written quote before any work starts.
How it works
- 1
Site Inspection
We examine the chimney from the roof and attic, checking flashing condition, mortar joints, and any signs of water intrusion on homes in Renton neighborhoods.
- 2
Material Selection
Select flashing type and gauge based on existing roof material and exposure, accounting for wet winter conditions common in King County.
- 3
Removal And Prep
Carefully lift shingles and remove old flashing without damaging the chimney or decking, then inspect for hidden rot.
- 4
New Flashing Install
Install step and counter flashing with correct overlaps and sealant at joints, then restore shingles for a watertight seal.
- 5
Final Check
Test the repair area and confirm no new leak paths before leaving the job site.
Pricing
Most chimney flashing repairs in Renton fall between a few hundred and low thousand dollars depending on access and extent of hidden damage.