Licensed Waterproofing specialists serving Olney, MD with written warranties on every job, residential and commercial alike.

SGP Waterproofing is a licensed and insured Waterproofing contractor serving homeowners, property managers, and commercial building owners across Olney, MD. 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.
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 Olney, MD'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 Olney, MD 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 Olney, MD'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.
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.
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 Olney, MD 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.
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.
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.
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.
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.
We put the scope, materials, and price in writing so you can compare it against anyone else's estimate line for line.
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.
Same-day availability isn't guaranteed on every job, but our Olney, MD dispatch is built to prioritize it whenever the situation calls for it.
Our crews run truck-mounted extraction units, moisture meters, and thermal imaging cameras — not a shop-vac and a guess.
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.


We dispatch crews throughout Olney and the surrounding Olney, MD 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 Olney, MD: 20860 20832 20833 20853 20906 20830

"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."
— Olney 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."
— Olney 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."
— Olney 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."
— Olney 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."
— Olney 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."
— Olney Homeowner
For active flooding we prioritize same-day dispatch across our Olney, MD 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.
Pricing varies with scope, but every Olney, MD customer gets an itemized written estimate before any work is authorized, so there's never a guessing game.
No crack is too small to inspect; catching it early usually means a smaller repair bill down the road.
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.
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.
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.
One call gets you a licensed technician, a written quote, and a same-day time window.
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