We built SGP Waterproofing around one idea: a homeowner or property manager in Somerville, NJ shouldn't have to wait three days for someone to look at a wet wall.

SGP Waterproofing is a licensed and insured Waterproofing contractor serving homeowners, property managers, and commercial building owners across Somerville, 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.
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 Somerville, NJ response time beats most of the national franchises operating in the same zip codes.
Older Somerville, 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 Somerville, NJ inspection is checking for that kind of prior patch job before we recommend anything new.

Most Somerville, 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.
Those white, chalky mineral deposits on block or poured concrete walls are salt left behind after water has migrated through the concrete and evaporated.
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.
A window well that fills with water during heavy rain is putting direct pressure on the glass and frame, and it's one of the most common entry points we find in older Somerville, NJ homes.
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 Somerville, NJ 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.
When a sump pump fails during a storm or a foundation wall gives way, we dispatch a crew with portable pumps and extraction equipment within hours, not days.
Interior drain tile systems, sump pump installation, and vapor barrier wall systems make up the bulk of our residential basement work across Somerville, NJ neighborhoods.
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.
Encapsulation starts with removing standing water and debris, then sealing the space with a 12-20 mil liner and a dehumidifier sized to the cubic footage.
Extending downspouts another six to ten feet away from the foundation solves more Somerville, 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.
You get a flat-rate, itemized quote before any work starts — no verbal estimate that changes once the crew shows up.
Once installation wraps, we test the sump pump under load and walk you through the warranty paperwork before we leave the site.
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 Somerville, NJ dispatch is built to prioritize it whenever the situation calls for it.
Every technician trains on interior drain tile installation, sump system sizing, and crack classification before they lead a job on their own.
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 Somerville coverage area extends through most of the surrounding Somerville, NJ 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 Somerville, NJ: 08876 8876

"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."
— Somerville 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."
— Somerville Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— Somerville 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."
— Somerville 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."
— Somerville Property Manager
"We'd been dealing with musty smell in the basement for years and finally found out it was efflorescence building up behind the paint. Interior drain tile solved it for good."
— Somerville 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.
Pricing varies with scope, but every Somerville, NJ customer gets an itemized written estimate before any work is authorized, so there's never a guessing game.
We repair cracks of nearly any size — hairline cracks are often the easiest and least expensive to seal with polyurethane or epoxy injection before they widen.
The right system depends on access, budget, and what's actually driving the water in — we'll explain the trade-offs before you decide.
A single crack injection can be done in an afternoon, while a full interior drainage system typically runs two to three days start to finish.
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.
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.
Commercial scheduling is handled separately from residential dispatch so larger projects get the coordinated planning they need.
Call now for a free inspection and a flat-rate quote before anything gets worse.
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