RH Renovation NYC completed a precision custom copper chimney flashing replacement and masonry waterproofing project featuring hand-bent heavy-gauge copper step and counter-flashing, deep-reglet masonry mortising, soldered seam integration, and hydrophobic sealant application for a residential property located in the Bronx, NYC. The intersection where a masonry chimney meets a steep-slope roof deck is one of the most vulnerable water-infiltration points on any building envelope, particularly in the Bronx’s demanding urban microclimate.

Residential structures across the Bronx endure intense regional weather extremes—including high-velocity wind-shear funneled between closely spaced multi-story homes, driving rain from seasonal nor’easters, and severe winter freeze-thaw cycles. When legacy aluminum or galvanized flashing systems corrode, crack, or pull away from expanding brick mortar joints, rainwater migrates directly into the interior framing, rotting underlying roof decking, staining ceiling plaster, and causing masonry spalling. This project was engineered to replace failing flashing with a custom-fabricated, heavy-gauge copper flashing system—offering maximum flexibility, thermal resistance, and an impenetrable, lifetime watertight seal with timeless architectural elegance.

Comprehensive Scope of Work & Installation Methodology

To satisfy strict New York City Department of Buildings (DOB) roofing standards and deliver multi-decade leak protection, our licensed and insured Bronx roofing and sheet metal artisans executed a rigorous, multi-phase installation protocol:

• Legacy Flashing Removal & Substrate Remediation: Technicians carefully removed degraded old flashing, failing sealant tar, and compromised surrounding shingles around the chimney base. The brick surface and exposed wood roof subdeck were thoroughly cleaned, inspected, and repaired to establish a sound structural foundation.

• Self-Adhered Waterproof Membrane Underlayment: A high-tack, self-adhering ice-and-water shield membrane was applied directly to the bare deck and wrapped up the vertical face of the chimney base. This creates a secondary, redundant waterproofing barrier underneath the copper metalwork to catch any potential condensation or wind-driven moisture.

• Custom Copper Base & Step Flashing Integration: Heavy-gauge 16 oz. architectural copper base flashings and individual step flashing pieces were custom-bent on-site. The step flashings were meticulously woven layer-by-layer into each successive course of roofing shingles along the sides of the chimney to channel water fluidly down the roof slope.

• Deep Reglet Mortising & Interlocking Counter-Flashing: Technicians cut a clean, continuous horizontal reglet groove into the chimney mortar joints using dust-controlled diamond saws. Custom copper counter-flashing (cap flashing) pieces were inserted deep into the reglet, secured with lead expansion plugs, and hand-soldered or overlapped at all directional corner joints.

• High-Performance Sealant Application & Masonry Protection: The recessed reglet channel was packed with high-grade, non-sag polyurethane sealant to permanently seal the brick insertion point against driving rain. A breathable siloxane water-repellent sealer was applied to the surrounding masonry stack to prevent water absorption through the brick face.

• Final Quality Assurance & Detail Inspection: A comprehensive multi-point audit verified that all soldered lap joints, expansion folds, and reglet seals met strict architectural sheet metal standards and municipal building codes, followed by a complete site cleanup.

Project Highlights & Technical Specifications

• Service Category: Custom Architectural Copper Flashing Fabrication & Roof-to-Chimney Waterproofing

• Project Location: The Bronx, New York, NY

• Core Materials Used: 16 oz. cold-rolled architectural copper sheet metal, high-tack self-adhering ice-and-water shield membrane, lead expansion fasteners, non-sag polyurethane sealant, and 50/50 lead-tin solder.

• Key Engineering Focus: Hydrostatic roof-to-masonry transition sealing, thermal expansion/contraction accommodation, coastal wind-driven rain defense, and lifetime corrosion resistance.

Results & Homeowner Value

By installing a custom-fabricated, heavy-gauge copper flashing system, RH Renovation NYC permanently eliminated the persistent roof leak vulnerabilities around the chimney base. The Bronx homeowners now benefit from an impenetrable, maintenance-free waterproofing shield that withstands severe New York winters while gaining a striking architectural copper detail that elevates the property’s overall curb appeal and long-term equity.