Fort Collins homes built before 1990 in Old Town and near Old Town Square often have original skylights set into asphalt shingle roofs with basic step flashing that has pulled away after decades of expansion and contraction. Semi-arid conditions with cold winters drive rapid temperature swings that open small gaps at the skylight curb, letting snow melt and summer storms enter the attic. We replace deteriorated lead or aluminum step flashing and install new counterflashing tucked under the shingles and sealed to the skylight frame with high-temperature butyl tape rated for our UV exposure.
Access on two-story homes in the Harmony neighborhood or near Colorado State University frequently requires scaffolding because roof pitches exceed 8:12 and nearby trees drop needles that trap moisture against the flashing. We also address jobs where previous sealant-only fixes have failed around skylights installed over rigid foam insulation, which compresses and leaves the flashing unsupported. Proper integration with existing underlayment and ice-and-water shield along the lower curb prevents water from traveling under the shingles toward interior ceilings.
Larimer County code requires flashing to extend at least 4 inches up the skylight curb and 6 inches onto the roof deck; we verify this during every repair and correct short or missing sections that are common on homes near Horsetooth Reservoir. Wind-driven rain from the foothills can push water under poorly lapped flashing on west-facing slopes, so we lap new pieces in the correct sequence and secure them with ring-shank nails rather than staples that loosen over time.
Technician insight
In Fort Collins, the thing that catches most people out with Skylight Flashing Repair is how quickly the freeze-thaw cycles around Horsetooth Reservoir crack old butyl sealant on homes built in the 1970s and 80s; homeowners often try another tube of caulk and the leak returns the next winter because the step flashing itself has lifted.
Old Town Skylight Leak After Heavy Snow
Water stains appeared on the ceiling of a 1978 home two blocks from Old Town Square following a March snowmelt. We found the original aluminum step flashing had corroded and no longer lapped correctly over the shingles. New copper step flashing and counterflashing were installed with fresh ice-and-water shield on the lower curb, and the leak stopped.
Skylight Flashing Repair Services We Offer
✓Step Flashing Replacement
Remove and replace corroded step flashing around skylight curbs on shingle roofs common in Downtown Fort Collins.
✓Counterflashing Installation
Install new metal counterflashing tucked into the skylight frame and sealed to prevent water entry during heavy spring rains.
✓Curb Seal Repair
Renew the seal between the skylight frame and wood curb where freeze-thaw cycles have opened gaps in older Prospect Park homes.
✓Lead Boot Replacement
Replace deteriorated lead or rubber boots on plumbing vents adjacent to skylights that allow water to migrate under flashing.
✓Ice and Water Shield Integration
Add or repair ice-and-water shield under new flashing on lower skylight edges to block wind-driven moisture in Larimer County winters.
Skylight Flashing Repair Cost in Fort Collins, CO
| Service | Typical Range | What Affects It |
|---|---|---|
| Single Skylight Flashing Repair | $350–$650 | One-story homes in Old Town with easy access. |
| Two-Story Skylight Repair | $550–$950 | Scaffolding required near Colorado State University or Harmony. |
| Flashing Plus Underlayment Patch | $450–$800 | When ice-and-water shield must be replaced under shingles. |
| Multiple Skylight Repair | $800–$1,400 | Homes in Prospect Park with two or more skylights. |
Ranges are typical for Fort Collins, CO and confirmed with an exact written quote before any work starts.
How it works
- 1
Roof Inspection
We climb the roof and document flashing condition, shingle overlap, and any water stains visible from the attic access point.
- 2
Material Removal
Old flashing and sealant are carefully removed without damaging surrounding shingles or the skylight curb.
- 3
New Flashing Fit
Custom-cut step flashing and counterflashing are installed with proper laps and high-temperature sealant compatible with local temperature swings.
- 4
Final Water Test
We spray the repaired area to confirm no water enters before leaving the site.
Pricing
Most skylight flashing repairs in Fort Collins fall between a few hundred and low thousand dollars depending on roof height, pitch, and whether additional underlayment work is needed.