Licensed Waterproofing specialists serving Greenlawn, NY with written warranties on every job, residential and commercial alike.

SGP Waterproofing is a licensed and insured Waterproofing contractor serving homeowners, property managers, and commercial building owners across Greenlawn, NY. We didn't start as a marketing company that added waterproofing to a service list — our crews came up running sump pumps, pouring interior drain tile, and injecting epoxy into foundation cracks long before the trucks had our name on the door.
Our dispatchers know the difference between a slow seep that can wait until morning and an active flood that can't, and they route calls accordingly. That triage system is the reason our average Greenlawn, NY response time beats most of the national franchises operating in the same zip codes.
Freeze-thaw cycles, seasonal rainfall patterns, and water table depth all shift how urgently a given crack or seep needs attention in Greenlawn, NY specifically. We track these patterns because they change how we prioritize scheduling during storm season versus a slow drip in the middle of a dry month.
We also see a lot of properties where a previous waterproofing attempt only addressed the symptom — a topical sealant painted over a cracked wall, for example — without solving the pressure or grading issue causing the crack in the first place. Part of every Greenlawn, NY inspection is checking for that kind of prior patch job before we recommend anything new.

Water damage rarely announces itself with a flooded basement on day one. It usually shows up as one of these smaller signals first, and Greenlawn, NY's seasonal moisture swings tend to speed the timeline up.
That damp, earthy smell in a finished or unfinished basement is usually mold or mildew feeding on moisture that's already gotten past your walls.
Those white, chalky mineral deposits on block or poured concrete walls are salt left behind after water has migrated through the concrete and evaporated.
Small stair-step cracks in block walls or vertical hairline cracks in poured walls tend to widen over a season or two as hydrostatic pressure keeps pushing.
Drywall that feels soft, bubbles, or shows a tide line near the floor is already absorbing groundwater — by the time you see it, the insulation behind it is usually soaked too.
If your window wells hold water for more than an hour after a storm, that water has nowhere to go but toward the seal around your basement window.
Puddling near the foundation that doesn't drain within a few hours usually means grading, gutters, or a failing perimeter drain — and it's the fastest path to a flooded basement.
We scope every Greenlawn, NY job in person before quoting it, because two houses with the same symptom rarely need the same fix. These are the five services that make up most of our workload.
Active flooding gets priority dispatch. We arrive with submersible pumps, air movers, and moisture-mapping tools to stop the water first and diagnose the long-term fix second.
We install interior perimeter drain systems tied into a sump basin, then finish the walls with a dimpled vapor barrier so any residual moisture is directed down, not trapped behind drywall.
Parking garages, below-grade retail space, and multi-family basements need waterproofing membranes and drainage systems rated for continuous traffic and higher hydrostatic load.
We classify every crack before injecting it — structural cracks get epoxy, active leaks get flexible polyurethane that expands to fill voids behind the wall.
A properly encapsulated crawl space with its own sump discharge line keeps humidity below the threshold where wood rot and mold can take hold.
Exterior French drains paired with corrected grading are usually the first thing we recommend for a property that's flooding from the outside in, not the inside out.
You describe what you're seeing and we ask a few questions to gauge urgency before anyone gets in a truck.
We walk the interior and exterior with a moisture meter and flashlight, tracing water back to its actual entry point instead of guessing.
We put the scope, materials, and price in writing so you can compare it against anyone else's estimate line for line.
Most residential jobs finish in one to three days, and we walk the property with you afterward to confirm every drain, pump, and seal is working.
Every quote breaks down materials and labor separately, so you can see exactly what you're paying for instead of one vague lump sum.
Same-day availability isn't guaranteed on every job, but our Greenlawn, NY dispatch is built to prioritize it whenever the situation calls for it.
We also carry Category 1, 2, and 3 water classification protocols for jobs where the source water isn't clean groundwater.
Warranty callbacks get the same dispatch priority as a new emergency, because a repeat leak is still an active problem for you.

Every interior drainage system, sump installation, and crack repair we complete in Greenlawn, NY comes with a written, transferable warranty — useful if you sell the property before the coverage period ends.


We dispatch crews throughout Greenlawn and the surrounding Greenlawn, NY service area, including the zip codes listed below. If you're just outside the boundary, call anyway — we often still make the trip.

Zip codes we serve in Greenlawn, NY: 11740 11743

"We had water coming in around the window well every time it rained hard. They regraded the area and sealed the well, and we haven't had a drop since."
— Greenlawn Homeowner
"We were selling the house and the inspector flagged a foundation crack. They came out within two days, injected epoxy, and gave us documentation for the buyer's lender."
— Greenlawn Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— Greenlawn Homeowner
"Sump pump failed overnight and flooded part of our storage room. New pump was installed with a backup battery the same afternoon we called."
— Greenlawn Customer
"Our parking garage had a persistent leak coming through the deck above the lower level. They installed a membrane system and coordinated the work around tenant parking so nobody was displaced."
— Greenlawn Property Manager
"They found the actual source of the dampness instead of just recommending a dehumidifier and calling it done. Been dry for over a year now."
— Greenlawn Homeowner
For active flooding we prioritize same-day dispatch across our Greenlawn, NY coverage area; routine inspections usually book within 48 hours.
We quote the full scope in writing after the inspection, so there's no hourly billing or surprise change orders once installation starts.
Our emergency response covers water extraction, temporary pump-outs, and emergency crack sealing to stop active intrusion until permanent repairs are scheduled.
Pricing varies with scope, but every Greenlawn, NY customer gets an itemized written estimate before any work is authorized, so there's never a guessing game.
No crack is too small to inspect; catching it early usually means a smaller repair bill down the road.
Depending on what the inspection finds, we'll recommend interior drainage, exterior grading and membrane work, or a combination of both.
Most residential interior drain tile or sump installations finish in one to three days; larger commercial membrane projects can take longer depending on square footage.
We can document moisture readings, photos, and scope of damage to support an insurance claim, though coverage and claim approval are ultimately determined by your carrier.
In most cases yes — a French drain collects water, but it still needs a sump pump to actually move that water out and away from the foundation.
We back our work with a written, often transferable warranty — useful if you sell the property before the coverage period runs out.
We assess the water depth and source first, since active groundwater intrusion changes how we sequence the encapsulation work.
We work with property managers, HOAs, and commercial building owners across Greenlawn, NY in addition to single-family homes, including parking structures and multi-unit basements.
One call gets you a licensed technician, a written quote, and a same-day time window.
Call +1-866-476-1348© SGP Waterproofing. All rights reserved.