Professional Waterproofing
to NYC Standards
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Waterproofing plays a crucial role in protecting building structures, especially in the densely populated environment of New York City. According to the city's Administrative Code, the floor of every bathroom must be waterproofed with approved materials, and this layer must extend at least 6 inches up the walls. A reliable waterproof barrier is the foundation for a long-lasting renovation and protects against financial losses from leaking into neighbors' apartments.
Contact UsWhat Our Process Includes
Co-op Rules
Navigating strict "Wet-over-Dry" rules that prohibit placing wet spaces over neighbors' dry living areas in multi-family buildings.
DOB Permits
All shower pan and plumbing work is accompanied by permits and performed by Licensed Master Plumbers (LMP) with mandatory rough-in inspections.
Lead Removal
Safe removal of old lead bends, common in pre-war buildings, and their reliable replacement with PVC systems.
Expert Inspections
Navigating Special Inspections (TR1) and energy efficiency infrastructure checks (TR8) by Special Inspection Agencies (SIA).
Subfloor Preparation
Using exclusively cement or extruded waterproof panels. We never use standard drywall in wet zones designated for tiling.
Membrane Installation
Applying liquid elastomeric or sheet waterproofing membranes that comply with ANSI A118.10 standards.
Flood Test
Conducting an official shower liner test: filling the pan with 2 inches of water for at least 15 minutes in accordance with the NYC Plumbing Code.
Final Finishes
Installing ceramic tile or natural stone using modified thin-set mortars after the waterproof barrier has fully cured.
When Waterproofing is Absolutely Essential
Waterproofing is a mandatory step during a gut bathroom renovation, when replacing outdated plumbing systems, or when converting a standard bathtub into a modern curbless shower. In older buildings, these measures help protect wooden joists from rot and structural damage. It is also required to clear municipal violations if the Department of Buildings issues a violation for a breach of Administrative Code § 27-2064 due to the lack of a waterproof floor. Proper waterproofing resolves the issue at the structural level.
The Role of Waterproofing in a Gut Renovation
This process is the central link of the entire renovation. Waterproofing is installed after the Licensed Master Plumber (LMP) has completed the rough plumbing and the Department has passed the Roughing Inspection. After applying the membrane and forming the pan, the system undergoes a rigorous flood test. Only after confirming that the monolithic barrier, which extends at least 6 inches up the walls, is completely watertight , can the installation of designer tiles begin.
See Waterproofing as Part of
a Real Bathroom Project
After
3D Rendering
Before
Planning a bathroom renovation
or targeted bathroom upgrade?
Contact DNB Renovations for a detailed quote.
Waterproofing for Different Property Types
Each building type in the city has its unique architectural
constraints and bureaucratic requirements for wet zones.
Pre-war Co-ops
Renovations require Board approval of an Alteration Agreement and strict adherence to the "Wet-over-Dry" rule. Often involves the removal of old lead plumbing.
Townhouses & Brownstones
Comprehensive services that include floor joist reinforcement and passing TR1 structural integrity inspections for wooden beams.
Condominiums
Custom curbless shower systems. May require compliance with Type A accessibility standards (ANSI A117.1-2009).
Frequently Asked Questions
About Bathroom Waterproofing
Our Comprehensive Services
Comprehensive renovation services designed to improve the flow,
function, and overall feel of your home.
Full Home Renovations
Turnkey services complying with all city architectural and engineering codes.
Bathroom Renovations
Specialized wet-zone remodeling strictly following your Co-op/Condo alteration agreements.
Kitchen Renovations
Creating functional kitchens tailored to modern ventilation and plumbing standards.
Start Your Renovation With Us
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