Waterproofing Contractor NYC
Waterproofing for NYC homes, co-ops, and commercial buildings, from wet basements and cracked foundations to leaking roofs, terraces, and sidewalk vaults. We find where the water is getting in, then fix it with the right system for that part of the building.
Licensed & Insured
Leak Source Found First
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Licensed & Insured Waterproofing Contractor
What a Waterproofing Contractor Does in NYC
A waterproofing contractor stops water from getting into a building, whether it’s pushing up through a basement floor, seeping through a foundation wall, or leaking through a roof, terrace, or exterior wall. The work always starts by finding the source, because water rarely shows up inside where it actually enters. From there, the fix depends on the location. Basements often need interior drainage and sealing, foundations need exterior membranes, cracks need injection, and roofs and terraces need new membranes and proper drainage.
New York City is hard on buildings when it comes to water. Heavy storms overwhelm drainage, groundwater presses against foundations in low-lying areas, winters freeze and crack anything that holds moisture, and many buildings still rely on waterproofing that’s decades old. A good waterproofing contractor understands all of that and chooses a system built for the specific leak, not a one-size-fits-all coating.
Where Is the Water Coming In?
Start with what you’re seeing. Each of these points to a different kind of waterproofing, and a different fix.
Water on the Basement Floor
Puddles or damp floors after rain. See basement waterproofing.
Leaking Foundation Walls
Water seeping through below-grade walls. See foundation waterproofing.
Cracks Letting Water In
Water tracing a crack in a concrete wall. See foundation crack repair.
Damp Stains on Exterior Walls
Wet patches on walls that face the weather. See exterior wall waterproofing.
Top-Floor Ceiling Leaks
Stains and drips below a flat roof. See roof waterproofing.
Leak Below a Terrace
Water in the apartment beneath a terrace or balcony. See terrace waterproofing.
Water in a Sidewalk Vault
Leaks into the space under the sidewalk. See sidewalk vault waterproofing.
Garage or Plaza Deck Leaks
Water through parking decks and plazas. See commercial waterproofing.
Waterproofing Services in NYC
Wet and damp basements fixed from the inside with sealing and interior drainage, so the space stays dry after every storm.
Exterior membranes and drainage applied to foundation walls, for new construction and major below-grade repairs.
Leaking cracks in concrete foundation walls sealed with injection, from the inside and without excavation.
Coatings and breathable water repellents that keep rain from soaking through a building’s exterior walls.
Flat roof membranes and coatings that stop leaks into top-floor apartments and offices.
Waterproofing membranes under terraces and balconies, so water stops reaching the apartments below.
Leaks into vaults beneath NYC sidewalks stopped, protecting basements, storage, and businesses below.
Garages, plaza decks, and large roofs and terraces waterproofed for commercial and residential buildings.
Why NYC Buildings Leak
Most leaks in the city come back to a few causes, and knowing them helps explain why the right fix matters.
Water Pushing From Below
Heavy rain and groundwater build pressure against foundations, forcing water through cracks and joints.
Freeze-Thaw & Age
Winters crack anything holding moisture, and older membranes and coatings wear out over time.
City-Specific Details
Flat roofs, terraces over apartments, and vaults under sidewalks all create places for water to collect.
Our Waterproofing Process in NYC
We don’t guess at leaks. Every job follows the same three steps.
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Find the Source
We inspect inside and out, and test where needed, to confirm exactly where the water is getting in.
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Choose the Right System
Membrane, coating, injection, or drainage, chosen for the location and the kind of leak.
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Install, Test & Walk Through
The system is installed, checked, and reviewed with you before we leave.
Waterproofing Systems We Use
There’s no single waterproofing product that works everywhere. These are the main systems we choose from.
Membranes
Sheet and liquid membranes for foundations, roofs, and terraces.
Coatings & Repellents
Protective coatings and breathable repellents for exterior walls.
Crack Injection
Injected resins that seal leaking cracks in concrete walls.
Drainage Systems
Interior and exterior drainage that carries water away before it builds up.
Why NYC Owners Choose Our Waterproofing Team
Many of the leaks we fix have already been waterproofed once, with a coating or patch that didn’t match the problem. We start with the source and build the fix around it.
Source Before Solution
No system chosen until we know where the water enters.
The Right System
Different leaks, different materials, not one product for everything.
Clean, Careful Work
Homes and apartments protected while we work inside.
Checked Before We Leave
Every job reviewed and tested where possible.
Waterproofing Work Backed in Writing
Waterproofing only proves itself when the next big storm hits. That’s why our work comes with written warranty terms that spell out what’s covered, for how long, and what happens if water comes back. You’ll see the terms before any work begins, so there are no surprises later.
- Written Warranty Terms
- Coverage Explained Upfront
- Covers the Work We Install
- Records of Every Job
- Clear Next Steps if a Leak Returns
Waterproofing Projects in NYC
What NYC Owners Say About Our Waterproofing
Waterproofing Across NYC & Westchester
We waterproof homes, co-ops, condos, and commercial buildings throughout four NYC boroughs and Westchester County.
Queens
Basements and foundations in houses across the borough.
Brooklyn
Row house basements, roofs, and terraces.
Manhattan
Terraces, roofs, and sidewalk vaults.
Bronx
Apartment building basements and roofs.
Westchester
Basement and foundation waterproofing in homes across the county.
Waterproofing Contractor FAQs
We handle basement and foundation waterproofing, foundation crack repair, exterior wall waterproofing, roof and terrace waterproofing, sidewalk vault waterproofing, and commercial waterproofing for garages and plaza decks.
We inspect the area inside and out, look at how the water shows up, and test where needed to confirm the entry point. Water often travels before it appears, so the source can be far from the stain.
Manhattan, Brooklyn, Queens, the Bronx, and Westchester County.
Yes. We're a licensed and insured contractor, and we provide certificates of insurance for co-op boards, property managers, and commercial owners.
Waterproofing stops the moisture that lets mold grow, which is the most important step. Mold that's already there needs to be cleaned up or remediated separately, and we'll tell you if what we see calls for it.
Some work, like interior crack injection and drainage, can be done year-round. Membranes and coatings need suitable temperatures and dry conditions, so roof, terrace, and exterior work is scheduled around the weather.
Call us or send photos of the leak through our quote form. We'll review them, visit the property, and give you a written estimate for the fix.