Basements flood, crawl spaces flood, and parking garages flood — usually at the worst possible hour. Our New London, WI technicians are staged and ready to respond the moment you call.

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.
Soil composition changes how much hydrostatic pressure builds against a foundation wall, and New London, WI's mix of clay-heavy and sandy soils behaves differently depending on the neighborhood, sometimes block to block. A crew that hasn't worked the area tends to size drainage systems using generic assumptions instead of what's actually under the yard.
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 New London, WI 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 New London, WI'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.
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.
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 New London, WI 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.
For finished basements we route the drain tile beneath the existing slab edge, which limits how much flooring has to come up during installation.
Parking garages, below-grade retail space, and multi-family basements need waterproofing membranes and drainage systems rated for continuous traffic and higher hydrostatic load.
Low-pressure epoxy injection bonds structural cracks back together, while polyurethane injection is better suited for cracks that are still actively leaking.
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.
We trace surface water back to its source, which is often a downspout discharging too close to the foundation or a grade that slopes the wrong direction entirely.
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.
We walk the interior and exterior with a moisture meter and flashlight, tracing water back to its actual entry point instead of guessing.
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.
Every quote breaks down materials and labor separately, so you can see exactly what you're paying for instead of one vague lump sum.
Because our crews are based in and around New London, WI, 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.


Our New London coverage area extends through most of the surrounding New London, WI 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 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
"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."
— New London 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."
— 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
"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."
— 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.
Pricing is disclosed in full before you sign anything, and we walk through each line item so nothing is a surprise later.
Emergency crews are equipped to stabilize the situation immediately, then schedule the permanent fix once the immediate flooding risk is under control.
We avoid quoting ballpark numbers over the phone because two basements with the same symptom can need very different fixes.
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.
The right system depends on access, budget, and what's actually driving the water in — we'll explain the trade-offs before you decide.
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.
A French drain without a sump pump just relocates water to one spot; the pump is what actually discharges it away from the home.
Warranty length and coverage vary by service type, and we'll spell out the specifics in writing before the job starts.
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 New London, WI 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.