We built SGP Waterproofing around one idea: a Northville, MI property owner shouldn't have to wait three days for someone to look at a wet wall.

We're a licensed, insured Waterproofing outfit built around Northville, MI properties specifically — the clay-heavy soil, the seasonal freeze-thaw cycles, the older basements with parged walls that were never meant to hold back a modern water table. Every technician on our crew has logged real hours crawling through wet crawl spaces, not just reading about them.
Because we staff locally instead of subcontracting out to whoever's available, the estimate you get over the phone tends to match the invoice you get at the end of the job — no surprise line items, no upsell script.
Soil composition changes how much hydrostatic pressure builds against a foundation wall, and Northville, MI'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.
Because we've worked enough Northville, MI 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 Northville, MI 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.
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.
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.
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 Northville, MI 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.
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 Northville, MI 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.
Most Northville, MI 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.
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.
We install heavy-gauge vapor barriers, seal foundation vents, and add a dedicated sump basin so a damp Northville, MI crawl space stops feeding moisture into the floor joists above it.
Extending downspouts another six to ten feet away from the foundation solves more Northville, MI drainage problems than people expect, and we'll usually check that before recommending anything more invasive.
You describe what you're seeing and we ask a few questions to gauge urgency before anyone gets in a truck.
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.
Once installation wraps, we test the sump pump under load and walk you through the warranty paperwork before we leave the site.
We quote the whole job as one flat number, so the price on the invoice matches the price we quoted on day one.
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.
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.


We dispatch crews throughout Northville and the surrounding Northville, MI 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 Northville, MI: 48167 48168

"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."
— Northville 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."
— Northville Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— Northville 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."
— Northville 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."
— Northville 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."
— Northville Homeowner
For active flooding we prioritize same-day dispatch across our Northville, MI 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.
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.
We're happy to provide the documentation adjusters typically request, though we recommend confirming your specific coverage details directly with your insurance provider.
A French drain without a sump pump just relocates water to one spot; the pump is what actually discharges it away from the home.
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.
We work with property managers, HOAs, and commercial building owners across Northville, MI in addition to single-family homes, including parking structures and multi-unit basements.
Call now for a free inspection and a flat-rate quote before anything gets worse.
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