From a hairline crack in the block wall to standing water in the crawl space, our Markham, IL crews handle it with flat-rate pricing and same-day dispatch.

SGP Waterproofing is a licensed and insured Waterproofing contractor serving homeowners, property managers, and commercial building owners across Markham, IL. 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.
Soil composition changes how much hydrostatic pressure builds against a foundation wall, and Markham, IL'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 Markham, IL 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 Markham, IL's seasonal moisture swings tend to speed the timeline up.
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.
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 Markham, IL 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 Markham, IL clients request most often.
A burst window well seal or a failed check valve can put inches of water in a basement in under an hour — our emergency crews carry truck-mounted extraction pumps and moisture meters to start mitigation the same day you call.
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.
Commercial jobs typically pair exterior membrane work with an interior collection system, since most existing commercial structures can't be fully excavated without major disruption.
We classify every crack before injecting it — structural cracks get epoxy, active leaks get flexible polyurethane that expands to fill voids behind the wall.
A properly encapsulated crawl space with its own sump discharge line keeps humidity below the threshold where wood rot and mold can take hold.
Extending downspouts another six to ten feet away from the foundation solves more Markham, IL 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.
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 Markham, IL, we're not routing your call through a national scheduling system that books you two weeks out.
Every technician trains on interior drain tile installation, sump system sizing, and crack classification before they lead a job on their own.
Warranty callbacks get the same dispatch priority as a new emergency, because a repeat leak is still an active problem for you.

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


Our Markham coverage area extends through most of the surrounding Markham, IL 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 Markham, IL: 60428

"Our basement flooded during a storm at 2am and someone actually picked up the phone. The crew had pumps running before sunrise and came back two days later to install the drain tile system."
— Markham 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."
— Markham Seller
"The crawl space under our addition never dried out properly. Full encapsulation with a dehumidifier fixed it in one visit."
— Markham 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."
— Markham 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."
— Markham 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."
— Markham Homeowner
For active flooding we prioritize same-day dispatch across our Markham, IL coverage area; routine inspections usually book within 48 hours.
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.
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.
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.
Documentation from our inspection often helps speed up the claims process, but final approval is always the insurer's call.
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.
Yes — we pump out existing standing water first, then move into encapsulation and sump installation once the space is dry enough to work in safely.
Yes — our commercial work covers parking garages, retail basements, and multi-family buildings, usually scheduled in phases to minimize tenant disruption.
Call now for a free inspection and a flat-rate quote before anything gets worse.
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