We diagnose the actual water source before we quote anything — no guessing, no upsell, just a plan sized to your property.

SGP Waterproofing is a licensed and insured Waterproofing contractor serving homeowners, property managers, and commercial building owners across Great Neck, 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.
We keep our crews local rather than routing calls through a national call center, which means the technician who answers your questions on the phone is often the same person standing in your basement two hours later. That continuity cuts down on the miscommunication that drags out so many waterproofing jobs.
Freeze-thaw cycles, seasonal rainfall patterns, and water table depth all shift how urgently a given crack or seep needs attention in Great Neck, 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 Great Neck, 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 Great Neck, NY's seasonal moisture swings tend to speed the timeline up.
A persistent musty smell almost always means moisture is present somewhere in the wall assembly, even if you can't see a wet spot yet.
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.
Bubbling paint or soft drywall near the baseboards is one of the last signs to show up, which means moisture has typically been present for weeks already.
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.
Water that pools against your foundation after every rain is telling you the drainage system, whatever's left of it, has stopped doing its job.
We scope every Great Neck, 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.
Once the water is out, we run air movers and dehumidifiers to bring humidity down before mold has a chance to establish itself in drywall or subfloor.
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.
We coordinate directly with building engineers and HOA boards so the scope, timeline, and access requirements are agreed on before a crew ever shows up on-site.
Crack injection is often the most cost-effective Great Neck, NY repair when the crack is isolated and the wall itself hasn't bowed or shifted.
A properly encapsulated crawl space with its own sump discharge line keeps humidity below the threshold where wood rot and mold can take hold.
Sometimes the fix isn't inside the wall at all — regrading the soil away from the foundation and adding a French drain can solve a moisture problem before water ever reaches the block.
A dispatcher walks through symptoms with you on the phone so the crew that shows up already has a rough idea what they're dealing with.
A technician maps moisture readings, checks grading, and identifies whether the source is groundwater, surface water, or condensation.
You get a flat-rate, itemized quote before any work starts — no verbal estimate that changes once the crew shows up.
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.
You'll know the total cost before we start — no hourly billing, no surprise add-ons once the walls are already open.
Because our crews are based in and around Great Neck, NY, we're not routing your call through a national scheduling system that books you two weeks out.
We also carry Category 1, 2, and 3 water classification protocols for jobs where the source water isn't clean groundwater.
If a sealed crack reopens or a sump system underperforms within the warranty window, we come back and make it right at no extra charge.

We document every job with photos, moisture readings, and a copy of the warranty terms, so there's a paper trail if you ever need to reference the work again.


Our Great Neck coverage area extends through most of the surrounding Great Neck, NY communities. Give us a call even if your address falls just outside the zone below; we'll let you know honestly if we can reach you same-day.

Zip codes we serve in Great Neck, NY: 11024 11023 11027 11020 11021

"Our basement flooded during a storm at 2am and someone actually picked up the phone. The crew had pumps running before sunrise and came back two days later to install the drain tile system."
— Great Neck Homeowner
"The crack in our basement wall had been leaking for a year before we finally called. Injection took less than an afternoon and it's been dry since."
— Great Neck Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— Great Neck 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."
— Great Neck Customer
"Property management hired them to fix water coming through the garage ceiling. They scheduled the membrane work in phases so we never had to close the whole garage."
— Great Neck 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."
— Great Neck Homeowner
Response time depends on call volume and severity, but emergency water intrusion always jumps the queue ahead of routine estimates.
Yes — every job gets a flat-rate, written quote before work begins, and that number doesn't change once the crew is on-site.
We handle active flooding, sump pump failures, and failed foundation walls with same-day dispatch, portable extraction pumps, and temporary water mitigation.
Cost depends on square footage, the type of system needed, and whether the fix is interior drainage, exterior membrane work, or both — we won't quote a number without an in-person inspection first.
No crack is too small to inspect; catching it early usually means a smaller repair bill down the road.
We install both — interior drain tile and sump systems for most residential jobs, and exterior membrane or French drain systems when the source is surface water or when excavation is practical.
We give you a realistic timeline in the written quote so you can plan around the crew being on-site.
Documentation from our inspection often helps speed up the claims process, but final approval is always the insurer's call.
We can walk your specific setup during an inspection and tell you honestly whether your existing drain needs a pump added.
Yes, every interior drainage, sump, and crack repair job comes with a written warranty, and terms are explained in full before you approve the quote.
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 Great Neck, 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.
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