Worn flashing causes most cases of a roof leak around the chimney. Serving 730+ towns across Massachusetts, New Hampshire and Maine, Coastal Windows & Exteriors is a woman-owned exterior remodeling company with GAF Master Elite and GAF Green Certified status and 7,000+ installations completed since 2011. Every roof we install includes a flashing review around the chimney, so small gaps get sealed before they turn into ceiling stains. Here’s where water usually sneaks past the masonry.
Where Water Sneaks Past the Masonry
- Flashing Separation: Metal flashing seals the joint between brick and shingles. Seasonal expansion loosens that seal, giving rain a direct path into your attic.
- Deteriorating Mortar: Crumbling joints let water soak through the chimney itself. Stains then appear on ceilings well away from where moisture entered.
- Ice Dam Backup: Snow melts over a warm attic and refreezes at the cold eave. Removing an ice dam can cost up to $4,000 before any repairs begin.
- Hidden Interior Damage: Leak repair after an ice dam can climb as high as $24,000. Wet insulation and stained drywall often surface long after the storm passes.
- Drifts Around the Stack: Wind piles snow against the uphill side of wide chimneys. Read up on snowfall dangers to your roof before the first big storm arrives.
- Shingle Damage Nearby: Water lingering near the chimney weakens surrounding shingles over time. Shingle repairs after ice dam events range from $130 to $9,000.
- Prevention Pays Off: Heat cable installation runs $500 to $4,600. That’s a fraction of what one damaging winter can cost.
Stopping a Chimney Leak for Good
Top Recommendation: New flashing plus leak barrier at the chimney base, since most leaks start at the metal.
Best for Budget: Targeted flashing repair when the surrounding shingles remain in solid shape.
Best for Ice-Prone Roofs: Balanced ventilation that keeps the attic cold and stops ice dams from forming.
Spotted a stain near the chimney? Get it inspected before the next hard freeze. Every inspection ends with a clear written report.
Request a free roofing estimate from Coastal Windows & Exteriors.
Browse our complete roofing FAQ guide from Coastal Windows & Exteriors.
Explore the Coastal Windows & Exteriors Roofing Exterior Remodeling Home Improvement Help Center.
Still have questions about what causes a roof leak around the chimney? See the areas we serve and talk to your local roofing contractor.
Last Updated: September 2026
Sources:
- Ice dam removal can cost up to $4,000. Angi Ice Dam Removal Cost, Angi’s pricing guide for ice dam removal and follow-up repairs. (2025)
- Roof leak repair after ice dam removal can cost up to $24,000. Angi Ice Dam Removal Cost, Angi’s breakdown of interior leak repair costs tied to ice dams. (2025)
- Shingle repairs following ice dam damage range from $130 to $9,000. Angi Ice Dam Removal Cost, Angi’s estimate range for shingle damage after winter ice buildup. (2025)
- Heat cable installation costs $500 to $4,600. Angi Ice Dam Removal Cost, Angi’s figures on preventive ice dam measures. (2025)
