Chimney Flashing Repair - Northwest Chicago Suburbs
"The metal seal between your chimney and roof is only as good as the mortar holding it. When that fails, your ceiling pays the price."
Chimney flashing is the metal seal between your chimney and your roof — and when it fails, water gets in. Flashing failure is one of the most common causes of roof leaks in the Chicago suburbs. GEM Chimney & Duct repairs and replaces chimney flashing for homeowners throughout Wheeling and the northwest Chicago area.
Water entering through failed flashing can travel inside wall cavities and attic spaces for months before becoming visible as a ceiling stain. By the time you see the stain, the water may have already caused mold growth and structural damage to roof decking and framing.
What Is Chimney Flashing Repair?
Chimney flashing consists of two components: step flashing (L-shaped pieces of metal that interleave with the roof shingles along the sides of the chimney) and counter flashing (metal that's embedded in the chimney mortar joints and laps over the step flashing). Together, they create a watertight seal at the chimney-roof junction. Flashing is typically made of aluminum, galvanized steel, or copper. Over time, the mortar holding counter flashing in place deteriorates, the metal corrodes or separates, and the seal fails.
Failed chimney flashing is one of the top three causes of roof leaks in older homes. Water that enters through failed flashing can damage roof decking, attic insulation, ceiling drywall, and wall framing. In Illinois winters, ice dams can form at the chimney-roof junction and force water under the flashing. Addressing flashing failure promptly prevents far more expensive structural repairs.
Signs You Need It
- Water stains on the ceiling directly adjacent to the chimney
- Visible gaps between the flashing and the chimney masonry
- Rust stains running down the chimney exterior
- Flashing that's pulling away from the chimney or roof
- Caulk or tar patches on the flashing (sign of previous amateur repairs)
- Water in the firebox after rain
Our Chimney Flashing Repair Work
Chimney Flashing Repair in the Chicago Area: What You Need to Know
Illinois winters create a specific flashing failure mechanism that's more severe than in warmer climates: ice dams. When snow melts on a warm roof and refreezes at the cold chimney-roof junction, ice builds up and forces water under the flashing. Combined with the normal thermal expansion and contraction of metal flashing in our temperature extremes (from -10°F to 95°F), flashing in the northwest suburbs takes a beating that accelerates its failure timeline significantly.
Expert Tip from GEM
If you see caulk or tar patches on your chimney flashing, a previous owner or roofer tried to fix a leak with a temporary patch. Caulk fails within 1–3 seasons. The only permanent fix is proper step and counter flashing installation. Don't let a roofer talk you into another caulk patch.
Before & After
Before GEM
Counter flashing pulling away from chimney mortar joints. Step flashing corroded and separated from shingles. Water entering at chimney-roof junction, staining ceiling adjacent to chimney.
After GEM
New step and counter flashing properly installed and embedded in fresh mortar. All joints sealed with roofing sealant. Leak stopped. Surrounding roof area inspected for related damage.
Our Chimney Flashing Repair Process
Leak source confirmation
We inspect the full chimney-roof junction to confirm flashing failure is the source of the leak and identify whether step flashing, counter flashing, or both need attention — ruling out crown and cap as contributing factors.
Old flashing removal
We carefully remove the failed flashing, clean the substrate, and prepare the chimney mortar joints for new counter flashing installation. We remove all old caulk and tar patches.
New flashing installation
We install new step and counter flashing using appropriate materials (aluminum, galvanized steel, or copper), properly interlacing with the roof shingles and embedding counter flashing in fresh mortar.
Sealing and final inspection
We apply a high-quality roofing sealant at all joints and transitions, and inspect the surrounding roof area for any related damage that should be addressed.
Typical Pricing
All pricing is upfront — we provide a written estimate before any work begins. No surprises.
| Service | Typical Range |
|---|---|
| Counter flashing re-embedding (mortar only) | $200–$400 |
| Full flashing repair (step + counter) | $400–$700 |
| Full flashing replacement with copper | $700–$1,200 |
Chimney flashing repair typically runs $300–$600 for a standard single-flue chimney. Full flashing replacement (both step and counter flashing) ranges from $500–$900. Copper flashing, which is more durable and longer-lasting, costs more but can last 50+ years. The cost of flashing repair is almost always less than the cost of repairing the water damage caused by failed flashing.
Why Homeowners Choose GEM for Chimney Flashing Repair
Registered in Illinois
We operate as a registered business in Illinois — not a fly-by-night operation.
Fully Insured
General liability insurance protects you and your home on every job.
Written Inspection Reports
Every service includes a written report documenting what was found and completed.
Upfront Pricing
We provide a written estimate before any work begins. No surprises on the invoice.
Same-Day Scheduling
Urgent situations get priority — same-day appointments available when needed.
10+ Years Serving the Northwest Suburbs
We've built our reputation one honest job at a time across 24 communities.
Schedule Chimney Flashing Repair Today
Same-day scheduling available — takes 30 seconds.
Frequently Asked Questions About Chimney Flashing Repair
Related Services
Chimney Flashing Repair — All Service Areas
We provide chimney flashing repair throughout the northwest Chicago suburbs. Click your city for local pricing and details.