Project: Existing Flat Roof Power Wash in Mt Vernon

RH Renovation NYC completed a comprehensive low-slope flat roof restoration project featuring high-pressure power wash surface preparation, targeted substrate remediation, and a commercial-grade rubber membrane waterproofing overlay for a property located in Mount Vernon, Westchester County, NY. Flat roofing assemblies throughout Mount Vernon and southern Westchester face severe environmental exposure—including organic debris accumulation, severe urban thermal loading, driving rains from seasonal nor’easters, and harsh winter freeze-thaw cycles.

Over time, atmospheric dust, moss, and airborne pollutants form a dense surface film over flat roof membranes. This residue holds standing water against seams, accelerates UV breakdown, and hides developing membrane punctures. When underlying substrate degradation occurs, unaddressed micro-cracks allow moisture to infiltrate thermal insulation and timber decking. This project was engineered to execute a rigorous restoration protocol: systematically power washing the roof field to restore surface cleanliness and adhesion conditions, repairing underlying substrate defects, and applying a heavy-duty rubber membrane overlay to establish an impenetrable waterproof seal across the entire building envelope.

Comprehensive Scope of Work & Installation Methodology

To adhere strictly to Westchester County and Mount Vernon municipal building codes, our licensed and insured commercial roofing specialists executed a precise, multi-phase technical installation protocol:

• High-Pressure Surface Decontamination & Power Wash: Technicians executed a high-pressure washing regimen across the entire flat roof field. This critical preparation phase stripped away built-up silt, moss, biological growth, and chalked coatings, exposing the raw substrate for full inspection and guaranteeing optimal mechanical adhesion for subsequent layers.

• Substrate Diagnostics & Targeted Remediation: A thorough surface-probe audit was conducted to locate underlying moisture traps, loose lap seams, and compromised decking panels. Saturated insulation and damaged membrane sections were excised and replaced with sound materials to create a solid, dry, and level foundation.

• Commercial Rubber Membrane Overlay Laydown: A premium, polyester-reinforced SBS/APP modified bitumen rubber membrane layer (Firestone 180) was unrolled, relaxed, and fully adhered/heat-welded across the prepared roof plane. Overlap seams were fused to achieve complete compound bleed-out, forming a continuous, puncture-resistant elastomeric barrier capable of absorbing thermal expansion and contraction.

• Parapet Wall & Edge Flashing Integration: All vertical transitions—including brick parapet walls, roof scuppers, drain basins, skylight curb bases, and vent pipes—were encased in heavy-duty membrane flashing boots, secured with aluminum termination bars, and sealed with non-sag exterior polyurethane lap sealants.

• Final Seam-Probe Inspection & Flow Audit: A multi-point quality assurance audit was performed across all field lap joints and edge terminations to verify seam tightness and unhindered runoff toward drainage outlets, followed by a thorough site cleanup.

Project Highlights & Technical Specifications

• Service Category: Commercial & Residential Low-Slope Flat Roof Power Washing, Repair & Rubber Membrane Waterproofing Overlay

• Project Location: Mount Vernon, Westchester County, NY

• Core Materials Used: Commercial-grade Firestone 180 polyester-reinforced rubber membrane layer, structural repair sheathing, heavy-gauge aluminum termination bars, prefabricated pipe flashing boots, non-sag polyurethane lap sealants, and eco-friendly surface cleaning agents.

• Key Engineering Focus: High-pressure surface decontamination, substrate seam stabilization, elastomeric thermal cycling resilience, hydrostatic leak elimination, and Mount Vernon municipal code compliance.

Results & Property Owner Value

By combining high-pressure power wash cleaning with targeted substrate repairs and a heavy-duty Firestone rubber membrane overlay, RH Renovation NYC permanently resolved the property’s water intrusion vulnerabilities. The Mount Vernon property owner now benefits from a fully restored, watertight, and resilient flat roof assembly engineered to resist harsh regional weather and extend the service life of the building.