Chimney Flashing Repair in Minneapolis
Your Roof Was Fine. The Flashing Was the Problem.
Counter Flashing
Embeds into a reglet channel cut in the mortar joint
Laps over the step flashing below it
Fails first — the reglet erodes under freeze-thaw
Step Flashing
Individual L-shaped pieces between shingle courses
Woven against the chimney side wall
Typically fails second, if at all
Minneapolis Chimneys and the Reglet Erosion Behind Flashing Failures
What I Find When I Get on the Roof
What Documentation Do I Actually Receive?
ChimTech's Flashing Repair Standards
Fresh reglet cutting — no attempt to re-anchor flashing into an eroded joint.
Flashing re-seated into the new channel before any sealant is applied.
UV-stable, flexible sealant rated for Minneapolis extremes — subzero to 90°F+.
Material-specific selection — stainless steel, aluminum, or copper matched to the existing installation where possible.
Step flashing inspection included — the lower layer is checked while we have access to the roof junction.
Written job record — reglet location, flashing material, sealant product, service date.
From Diagnosis to Completed Documentation
Flashing Diagnostics
ChimTech starts at the symptoms and works backward to the source — assessing counter flashing separation at the chimney face (measuring the gap, checking reglet depth, evaluating the mortar joint above and below the flashing seat) and inspecting step flashing at each course for secondary entry points. The assessment tells us exactly what needs to happen; we don't recommend repairs for components that are sound.
Re-Seating & Sealing
Once the scope is confirmed in writing, we cut a fresh reglet at the correct depth, re-seat the counter flashing into the new channel pressed flush against the face, and apply the flexible, UV-stable sealant over the reglet against freeze-thaw cycling, wind-driven rain, and summer heat expansion. If step flashing at any course shows separation or improper bedding, it's addressed in the same visit.
Post-Service Verification & Documentation
We verify the seal visually before leaving the roof, then complete the written job record on-site — reglet location, materials used, sealant product and temperature rating, and date of service. The homeowner receives a copy before we leave.
Where ChimTech Performs Chimney Flashing Repair
Ready to Fix the Flashing?
Frequently Asked Questions — Chimney Flashing Repair
Counter flashing is the upper metal component embedded into a channel cut in the chimney’s mortar joint; step flashing is the individual L-shaped pieces woven between shingle courses and the chimney side wall. In Minneapolis, counter flashing fails first in the majority of cases because its anchor — the mortar joint reglet — erodes under freeze-thaw pressure. Step flashing typically fails second, either from improper original installation or from moisture that entered behind failed counter flashing and worked underneath it.
The step flashing at the shingle level is within a roofer’s scope. The counter flashing and the mortar joint reglet that anchors it to the chimney face are chimney masonry work. When a roofer addresses only the shingle-level flashing without touching the reglet, the counter flashing separation continues and so does the water entry. ChimTech handles both the reglet cutting and the counter flashing re-seating as chimney work, separate from the roofing scope.
Caulk over a failed reglet doesn’t restore the mechanical grip that holds counter flashing against the chimney face — the flashing keeps pulling away behind the caulk bead. Minneapolis temperature swings, subzero winters to 90°F summers, crack and separate the caulk within one to two seasons even with a quality product. The only repair that holds is cutting a fresh reglet and re-seating the flashing into the new channel.
The pattern of moisture entry is the starting point. If the stain appears at the ceiling directly adjacent to the chimney but the shingles are intact and the roof isn’t leaking elsewhere, the chimney-roof junction is the likely source — counter flashing separation lets water run behind the flashing and down the face, reaching the interior through the roof deck at that junction rather than through the shingles. A ChimTech assessment identifies the entry point precisely before any repair begins.
ChimTech selects stainless steel, aluminum, or copper flashing based on the existing installation at each chimney, and the reglet sealant is a flexible, UV-stable compound rated for the full Minneapolis temperature range — subzero January lows through summer heat. Material selection and product used are documented in the job record. When the reglet is cut correctly and the flashing properly seated, a Minneapolis flashing repair should remain watertight for a decade or more under normal conditions.
Yes. ChimTech inspects the step flashing at each course along the chimney side wall during every counter flashing repair. Because both systems are accessible from the same roof position, it makes no practical sense to address the counter flashing without verifying the step flashing below it. If step flashing has lifted or is improperly bedded at any course, that’s addressed in the same visit — and we don’t recommend repairs for courses that are sound.