We diagnose the real source of the water before quoting 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 Closter, NJ. 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.
Older Closter, NJ neighborhoods often have block foundations poured decades before modern drainage codes existed, while newer subdivisions tend to run poured concrete with a perimeter drain that was installed correctly but has since clogged with silt. Knowing which era of construction you're dealing with changes the repair plan before a single tool comes out of the truck.
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 Closter, NJ inspection is checking for that kind of prior patch job before we recommend anything new.

Most Closter, NJ water intrusion problems don't start as a flood — they start small, and they get worse on a schedule. Here's what our technicians look for on a first inspection.
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.
Efflorescence forms when water carries dissolved minerals through porous concrete and leaves them on the surface as it dries — a clear sign moisture is actively passing through.
A crack that's a sixteenth of an inch wide today can become a sixteenth of an inch wider by next spring if the pressure behind the wall isn't relieved.
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.
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.
Every job starts with the same on-site inspection, whether it's a single crack or a full interior drainage retrofit. Below are the services Closter, NJ clients request most often.
A burst window well seal or a failed check valve can put inches of water in a basement in under an hour — our emergency crews carry truck-mounted extraction pumps and moisture meters to start mitigation the same day you call.
Most Closter, NJ basements need a combination of interior drainage and a properly sized sump pump — we size the system to your square footage and soil type, not a one-size-fits-all package.
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.
Extending downspouts another six to ten feet away from the foundation solves more Closter, NJ drainage problems than people expect, and we'll usually check that before recommending anything more invasive.
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.
We put the scope, materials, and price in writing so you can compare it against anyone else's estimate line for line.
Once installation wraps, we test the sump pump under load and walk you through the warranty paperwork before we leave the site.
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 Closter, NJ, 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.
Warranty callbacks get the same dispatch priority as a new emergency, because a repeat leak is still an active problem for you.

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.


We dispatch crews throughout Closter and the surrounding Closter, NJ 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 Closter, NJ: 07624 7624

"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."
— Closter 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."
— Closter Seller
"Our crawl space had standing water and a mold smell we couldn't get rid of. They pumped it out, encapsulated the whole thing, and added a dedicated sump discharge line."
— Closter Homeowner
"Our old sump pump died during the biggest storm of the year and we got water in the finished basement. They replaced it with a battery backup system so we're covered even during a power outage."
— Closter 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."
— Closter 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."
— Closter Homeowner
For active flooding we prioritize same-day dispatch across our Closter, NJ coverage area; routine inspections usually book within 48 hours.
Yes — every job gets a flat-rate, written quote before work begins, and that number doesn't change once the crew is on-site.
Our emergency response covers water extraction, temporary pump-outs, and emergency crack sealing to stop active intrusion until permanent repairs are scheduled.
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.
Hairline cracks are actually the ideal time to call, since injection repair is faster and cheaper before hydrostatic pressure has a chance to widen the gap.
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.
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.
We can walk your specific setup during an inspection and tell you honestly whether your existing drain needs a pump added.
We back our work with a written, often transferable warranty — useful if you sell the property before the coverage period runs out.
Standing water doesn't stop us from starting; we extract it as the first step, then proceed with vapor barrier and drainage installation.
Yes — our commercial work covers parking garages, retail basements, and multi-family buildings, usually scheduled in phases to minimize tenant disruption.
One call gets you a licensed technician, a written quote, and a same-day time window.
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