Licensed Waterproofing specialists serving Kensington, 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 Kensington, 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.
Older Kensington, MD 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 Kensington, 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 Kensington, 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.
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.
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 Kensington, MD 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 Kensington, MD clients request most often.
Active flooding gets priority dispatch. We arrive with submersible pumps, air movers, and moisture-mapping tools to stop the water first and diagnose the long-term fix second.
For finished basements we route the drain tile beneath the existing slab edge, which limits how much flooring has to come up during installation.
We work with property managers on phased scheduling so a commercial waterproofing retrofit doesn't shut down an entire building at once.
We classify every crack before injecting it — structural cracks get epoxy, active leaks get flexible polyurethane that expands to fill voids behind the wall.
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.
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.
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.
Same-day availability isn't guaranteed on every job, but our Kensington, MD dispatch is built to prioritize it whenever the situation calls for it.
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.

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


We dispatch crews throughout Kensington and the surrounding Kensington, 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 Kensington, MD: 20895 20891

"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."
— Kensington 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."
— Kensington 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."
— Kensington 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."
— Kensington 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."
— Kensington 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."
— Kensington Homeowner
Most Kensington, MD emergency calls get a technician on-site within a few hours; non-urgent inspections are typically scheduled within one to two business days.
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.
Cost depends on square footage, the type of system needed, and whether the fix is interior drainage, exterior membrane work, or both — we won't quote a number without an in-person inspection first.
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.
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.
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.
We assess the water depth and source first, since active groundwater intrusion changes how we sequence the encapsulation work.
Commercial scheduling is handled separately from residential dispatch so larger projects get the coordinated planning they need.
One call gets you a licensed technician, a written quote, and a same-day time window.
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