Spokane's freeze-thaw cycles and heavy winter snow loads push water under step flashing and around penetrations faster than in milder climates. On South Hill and Manito homes built before 1960, original lead or copper flashing often fatigues at the bends, allowing meltwater to reach sheathing during the March thaw. We replace or overlay these sections with 26-gauge galvanized or copper step flashing bedded in high-grade polyurethane sealant rated for -20°F, then counter-flash with new siding returns where needed.
Valley flashing on Spokane Valley split-levels sees extra stress from pine needle debris that holds moisture against the metal. We remove the old valley, inspect for rotted decking, install new 16-inch W-metal valleys with hemmed edges, and seal the laps with butyl tape plus a compatible elastomeric coating. This approach handles the 40-plus inches of annual snowfall without the buckling that thinner aftermarket valleys develop.
Skylight and plumbing vent boots on Browne's Addition bungalows frequently fail where the original neoprene has oxidized. We cut back the shingles, install new lead or high-temperature silicone boots, and weave them into the existing courses so the seal sits flat under the next row. Every edge receives a 3/8-inch bead of sealant that remains flexible through repeated freeze cycles.
Wall-to-roof transitions on east-facing slopes catch the worst of Spokane's prevailing winter winds. We install new L-shaped counter-flashing into a reglet cut in the stucco or brick, then seal the top with backer rod and polyurethane so wind-driven rain cannot reach the step flashing below.
Technician insight
In Spokane the thing that catches most people out with flashing and sealing is the way March meltwater finds every hairline crack in old step flashing on South Hill homes that still have original 1940s lead; once the ice dam forms, water travels sideways under the shingles before anyone sees interior stains.
Manito Bungalow Leak After Heavy Snow
A homeowner on 29th Avenue noticed ceiling stains after the first big thaw. We found deteriorated valley flashing under years of pine needles where the metal had split at the center crease. We replaced the valley with 16-inch W-metal, sealed all laps, and re-laid the courses so the new metal sits flat under the next row of shingles.
Flashing and Sealing Services We Offer
✓Chimney Flashing Repair
Remove failed step flashing around masonry chimneys and reinstall with new counter-flashing to stop ice-dam leaks common on Spokane County roofs.
✓Skylight Sealing
Replace deteriorated skylight curbs and boots then seal the perimeter to prevent water intrusion during Spokane's spring melt.
✓Valley Flashing Replacement
Install wider W-metal valleys with sealed laps that handle heavy pine debris and snow loads in South Hill and Manito neighborhoods.
✓Pipe Boot Replacement
Swap cracked plumbing vent boots for high-temperature silicone or lead versions and weave them into existing shingles for long-term watertightness.
✓Wall Flashing Installation
Add or repair counter-flashing at roof-to-wall junctions on east-facing slopes that receive the strongest winter winds in Spokane.
Flashing and Sealing Cost in Spokane, WA
| Service | Typical Range | What Affects It |
|---|---|---|
| Chimney Flashing Repair | $350–$950 | Higher when masonry needs tuck-pointing or access requires scaffolding |
| Skylight Sealing | $275–$650 | Price rises with curb rebuild or custom flashing fabrication |
| Valley Flashing Replacement | $400–$1,100 | Longer valleys or rotted decking increase the range |
| Pipe Boot Replacement | $150–$400 | Multiple boots or steep-pitch access affect final cost |
Ranges are typical for Spokane, WA and confirmed with an exact written quote before any work starts.
How it works
- 1
On-Site Assessment
We walk the roof and attic to locate active leaks, check flashing condition, and note snow-load patterns typical for the neighborhood.
- 2
Material Selection
Choose gauge and alloy that match existing metal while upgrading sealant to products proven flexible through Spokane freeze-thaw cycles.
- 3
Removal and Prep
Carefully lift shingles, remove old flashing, inspect decking for rot, and clean all surfaces so new sealant bonds directly to substrate.
- 4
Installation and Sealing
Install new step, valley, or counter-flashing with proper overlaps, then apply continuous sealant beads at every joint and termination.
- 5
Final Walk and Documentation
Test drainage, photograph completed work, and provide the homeowner with care notes for the coming winter.
Pricing
Most flashing and sealing repairs in Spokane fall between a few hundred and low thousands depending on access and extent of decking repair.