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 Custer, 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.
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 Custer, WI 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 Custer, 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 Custer, 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.
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.
Drywall that feels soft, bubbles, or shows a tide line near the floor is already absorbing groundwater — by the time you see it, the insulation behind it is usually soaked too.
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.
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 Custer, WI clients request most often.
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.
If a wall is bowing rather than just cracked, we'll flag that during the inspection since injection alone won't address a structural deflection issue.
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.
We walk the interior and exterior with a moisture meter and flashlight, tracing water back to its actual entry point instead of guessing.
We put the scope, materials, and price in writing so you can compare it against anyone else's estimate line for line.
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.
Local staffing means the technician answering your call today can usually be on-site the same day, not on a waitlist behind out-of-town jobs.
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.

Warranty terms vary by scope of work, and our technician will walk through exactly what's covered before you sign off on the quote — nothing vague, nothing left to interpretation.


Our Custer coverage area extends through most of the surrounding Custer, 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 Custer, WI: 54423

"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."
— Custer 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."
— Custer 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."
— Custer 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."
— Custer 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."
— Custer 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."
— Custer Homeowner
For active flooding we prioritize same-day dispatch across our Custer, WI 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.
We handle active flooding, sump pump failures, and failed foundation walls with same-day dispatch, portable extraction pumps, and temporary water mitigation.
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.
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.
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.
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.
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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