In a city that never sleeps, water never stops finding a way in. From heavy rains and coastal humidity to aging infrastructure, NYC buildings face constant moisture pressure—and without proper waterproofing, that pressure turns into damage. At Falco Design & Construction, we’ve seen it all: flooded basements in Brooklyn, cracked foundations in Queens, roof leaks in Manhattan lofts. Waterproofing isn’t just preventive—it’s a smart, long-term investment.
What Is Waterproofing—and Why It Matters
Waterproofing seals a structure so water cannot penetrate walls, floors, or roofs. It combines materials, detailing, and drainage design to stop moisture before it causes mold, rot, and structural failure.
The Hidden Costs of Poor Waterproofing
- Mold remediation can exceed $10,000+
- Water damage may void insurance coverage
- Structural repairs can cost 5–10× more than prevention
- Persistent moisture reduces property value and tenant satisfaction
Common Waterproofing Problems in NYC Buildings
- Basement leaks & flooding after heavy rain
- Cracked or shifting foundations from hydrostatic pressure
- Roof ponding and membrane deterioration
- Leaking parapet walls allowing water into façades
- Poor drainage around the perimeter or on flat roofs
- Unsealed penetrations around skylights, vents, and window wells
Each issue requires a tailored solution—patching a visible leak won’t help if the root cause is pressure under the slab or clogged roof drains.
Types of Waterproofing Systems
1) Basement & Foundation Waterproofing
- Exterior membranes (bituminous or polymeric)
- Interior cementitious coatings and crack injection
- Drainage boards, French drains, and sump pumps
- Vapor barriers and proper slab detailing
Best for: Homes and multifamily buildings with damp basements or recurring seepage.
2) Roof Waterproofing
- TPO or EPDM membranes for flat surfaces
- Elastomeric coatings for flexible, UV-resistant protection
- Flashing repair & resealing at all penetrations
Best for: Commercial roofs, apartment buildings, townhomes, and terraces.
3) Façade & Masonry Waterproofing
- Silane/siloxane sealers (breathable repellents)
- Repointing mortar joints and repairing cracked masonry
- Parapet wall reconstruction and coping installation
Best for: Pre-war and mid-century buildings in Manhattan, Brooklyn, and Queens.
4) Balcony & Terrace Waterproofing
- Cementitious underlayments and sloping correction
- Liquid-applied membranes under tile/stone
- Slip-resistant topcoats for safety and durability
Best for: Condos, penthouses, and high-rise outdoor spaces.
Interior vs. Exterior Waterproofing—Which Is Better?
| Type | Description | Best For | Typical Cost Range |
|---|---|---|---|
| Interior | Applied to inside walls/floors to block moisture that has entered | Quick, cost-effective fixes; minimal excavation | $2,000–$6,000 |
| Exterior | Excavates around foundation; seals and drains from the outside | Long-term protection; addresses hydrostatic pressure | $8,000–$20,000+ |
| Combination | Integrates interior barriers with exterior membranes and drainage | Chronic flooding or high water tables | Varies by site conditions |
Falco’s approach: Inspect the full envelope—foundation, façades, roof, and drainage—to find the root cause, not just the symptom.
Our Waterproofing Process (Step-by-Step)
- Inspection & Moisture Mapping — Identify entry points with diagnostics
- Surface Preparation — Clean, grind, or excavate to sound substrate
- Repair & Patch — Seal cracks; replace damaged sections
- Membrane Installation — Coatings or sheets matched to conditions
- Drainage Integration — French drains, sumps, scuppers, or leaders
- Quality Check & Cleanup — Final inspection and documentation
How NYC’s Climate Impacts Waterproofing
NYC sees heavy rainfall, high humidity, and frequent winter freeze–thaw cycles. Buildings expand and contract, cracking concrete and deteriorating sealants. Falco specifies UV-resistant, flexible, cold-weather-rated systems to keep your building dry year-round.
Waterproofing for Commercial Buildings
- Flat roof waterproofing & reflective coatings
- Foundation sealing for multi-story structures
- Elevator pit & parking garage waterproofing
- Maintenance contracts for annual inspections and repairs
We meet NYC DOB standards and support programs like Local Law 11 façade maintenance for long-term building health.
Waterproofing Maintenance Tips
- Clean gutters and roof drains every 3–6 months
- Re-seal joints and penetrations annually
- Inspect after major storms
- Maintain grading so water flows away from foundations
- Schedule a professional inspection every 2 years
Why Choose Falco Design & Construction
- 20+ years of waterproofing expertise across NYC & NJ
- Certified applicators for leading membrane systems
- In-house crews—no subcontracting
- Licensed, insured, and DOB-compliant
- Transparent pricing, clear communication, and guaranteed workmanship
Request a Waterproofing Inspection
FAQ
How do I know if I need waterproofing?
Look for damp walls, musty odors, peeling paint, standing water, or recurring roof leaks. An inspection will confirm the source and best fix.
Is interior or exterior waterproofing better?
Exterior solutions last longer and address hydrostatic pressure, but interior methods are faster and less invasive. Many NYC properties benefit from a combination.
How long do waterproofing systems last?
Quality membranes and coatings can last 10–25 years or more with proper maintenance and drainage.
Do you work on commercial buildings?
Yes. We handle flat roofs, foundations, elevator pits, garages, and provide maintenance contracts for ongoing protection.
