We built SGP Waterproofing around one idea: a New London, WI property owner 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 New London, WI. 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 New London, WI 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 New London, WI 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.
Because we've worked enough New London, WI basements to recognize patterns, we can often tell within the first ten minutes of an inspection whether a problem is isolated or connected to a larger drainage issue affecting the whole block. That context shapes whether we recommend a small crack repair or a full interior system.

Most New London, WI 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.
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.
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 New London, WI 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.
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 New London, WI clients request most often.
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.
Most New London, WI 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.
We work with property managers on phased scheduling so a commercial waterproofing retrofit doesn't shut down an entire building at once.
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.
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.
You describe what you're seeing and we ask a few questions to gauge urgency before anyone gets in a truck.
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 New London, WI 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.
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.

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


We dispatch crews throughout New London and the surrounding New London, WI 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 New London, WI: 54961

"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."
— New London 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."
— New London Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— New London 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."
— New London 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."
— New London 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."
— New London Homeowner
Most New London, WI emergency calls get a technician on-site within a few hours; non-urgent inspections are typically scheduled within one to two business days.
We quote the full scope in writing after the inspection, so there's no hourly billing or surprise change orders once installation starts.
Emergency crews are equipped to stabilize the situation immediately, then schedule the permanent fix once the immediate flooding risk is under control.
Pricing varies with scope, but every New London, WI 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.
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.
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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