Arrow Tight Waterproofing deploys certified waterproofing crews across Kennett Square, PA. We diagnose the moisture path, seal it at the source, and back every job with a written guarantee — no vague patches, no callbacks.


We've spent years responding to flooded basements and seeping foundations across Kennett Square, PA. What we learned is simple: most water intrusion problems trace back to three root causes — hydrostatic pressure, improper grading, and compromised foundation walls. We fix all three, not just the symptom you can see.
Our process starts with a thermal imaging inspection and a moisture meter reading at multiple wall and floor elevations. That data drives the scope — we don't guess, and we don't sell you a $10,000 system when a $1,200 crack injection solves the problem.
Most basement floods don't start as floods. They start as these ignored details. If you see any of these in your Kennett Square property, schedule a free inspection before the damage compounds.
White powder on concrete means water has been migrating through your wall. The mineral deposits are left behind when water evaporates after passing through the block or poured wall.
Vertical cracks are often settling. Horizontal cracks in block foundations indicate lateral soil pressure — a structural emergency, not just a cosmetic issue.
Mold and mildew require only 24–48 hours of elevated moisture to colonize. A musty smell after rain means your vapor barrier has failed or doesn't exist.
Water at the wall-floor joint indicates that groundwater pressure is pushing beneath your slab. This entry point worsens with every wet season if not addressed at the source.
Paint and drywall absorb moisture vapor before you can see liquid water. Bubbling or peeling in a below-grade space is almost always a moisture problem, not a paint adhesion failure.
A sump pump that cycles every few minutes — or runs non-stop — is managing a groundwater situation your current system wasn't designed for. It will burn out, and the next flood won't wait for a replacement.
Rust streaks on foundation walls mean moisture is reaching and oxidizing the rebar or metal lath inside your block or poured concrete — water that deep is already compromising structural integrity.
Hairline slab cracks that weep during wet weather indicate hydrostatic pressure building under the slab. Left alone, that pressure will widen the cracks and lift sections of the floor.
Every moisture problem has a different source. We identify yours specifically before we quote anything — then we deploy the right system, not the most expensive one.
When hydrostatic pressure is the primary culprit, the most effective long-term solution is a properly engineered interior drainage system. We install sub-slab perforated drain tile around the perimeter of your basement — capturing water before it can rise above slab level — and route it to a sump pit equipped with a dual-pump configuration.
These systems don't fight hydrostatic pressure — they redirect it.
📞 Get a Free Drainage Quote →Full exterior waterproofing involves exposing your foundation to the footer depth, applying a crystalline or elastomeric waterproofing membrane, installing a geocomposite drainage mat, and placing exterior drain tile at the footing — the same specification used in new commercial construction.
We use SilkOate, UMARK, and other commercial-grade membrane systems — not the paint-on damp-proofing that deteriorates within a few years.
📞 Schedule an Exterior Assessment →Poured concrete foundation cracks are repaired from the interior using high-pressure polyurethane or epoxy injection — the appropriate chemistry depends on whether the crack is actively leaking or dry. Polyurethane foam expands into wet, actively leaking cracks and cures flexible, accommodating minor future movement. Epoxy injection is used in dry cracks where structural bond restoration is the goal.
Block wall repointing involves removing deteriorated mortar joints to a minimum depth of 3/4 inch and repacking with waterproof hydraulic mortar.
📞 Get a Crack Injection Estimate →Crawl spaces are the most overlooked moisture source in residential structures. An unencapsulated crawl space — even one that "never floods" — pumps humid air into your living area through the stack effect, raising indoor humidity, feeding mold growth in floor joists, and accelerating wood rot in your subfloor structure. Full encapsulation seals that air pathway permanently.
For crawl spaces with active water entry, we install a perimeter drain channel at the footer line, route it to an appropriate discharge point or sump.
📞 Schedule a Crawl Space Inspection →A sump pump is only as reliable as its installation and backup plan. We install primary pumps — typically 1/2 to 3/4 HP cast iron submersibles with a minimum 10-year rating — alongside battery-operated backup systems that activate automatically when your primary pump fails or power goes out.
For finished basements and properties with high groundwater, we recommend a dual-pump system: a primary submersible at normal operating level and a pedestal backup set two inches higher.
📞 Get a Sump System Quote →We excavate and regrade window wells to the proper dimension, install a gravel drain bed with a perforated pipe tied into your perimeter drainage system, and apply waterproof flashing around the window frame — stopping the entry point at the source instead of managing it inside.
Window well covers are a maintenance measure, not a waterproofing solution — but paired with proper drainage installation.
📞 Book a Window Well Assessment →There are a lot of waterproofing companies in PA. Here's what separates the ones who fix the problem from the ones who fix the symptom — and why Arrow Tight Waterproofing consistently lands on the right side of that line.
Our process starts with a thermal imaging scan and moisture meter readings at the wall surface, floor, and any visible crack or staining.
We purchase materials from professional waterproofing suppliers, not retail channels.
Arrow Tight Waterproofing holds an active contractor's license in PA and carries $2M general liability plus workers' compensation on every crew member.
We quote a fixed scope and a fixed price before any work begins.
Our drainage system installations carry a written warranty against water intrusion through the protected area for the life of the system.
Our emergency dispatch protocol means a technician assesses the situation within 60 minutes of your call in most of our PA service territory.
Call +1-866-476-1348 or fill out our contact form. A live dispatcher answers around the clock. We'll get your address and route a technician based on availability and urgency.
A certified technician visits your property, conducts a full moisture inspection including thermal imaging and meter readings, identifies every active entry point, and documents the drainage pattern. No high-pressure sales tactics — just data.
The proposal covers every item: materials, drainage footage, labor, discharge routing, and any permit fee. The number on the proposal is the number on the invoice.
{Our crew completes the installation to the approved scope. On completion, we conduct a post-installation moisture check, walk you through the system, and provide the written warranty documents registered to your property address.|Installation is completed by our direct-employee crew. We clean up the jobsite, verify pump function and discharge routing, take post-install moisture readings, and hand you the warranty documentation before we leave.}
If you've noticed any of the warning signs above, the damage is compounding with every wet event. A free inspection costs you nothing; a delayed repair can cost thousands more.
📞 Get a Free Assessment: +1-866-476-1348"The crew showed up within 3 hours of my call at 9 PM on a Tuesday. I had water coming in through a crack in my poured wall at the floor joint — had been watching it for two seasons and finally called when it started spreading. They installed an interior drain system along two walls and a new sump pit. The work took two days. I've had three major rain events since then — completely dry. Worth every dollar.Highly recommend the whole crew."
"I've had two other companies look at my foundation crack before these guys. Both gave me vague proposals and neither one could tell me exactly why I had water or where it was coming in. Arrow Tight Waterproofing came out, brought a thermal camera, and showed me on screen exactly where the moisture was concentrated. The polyurethane injection they did on the crack has held for 18 months now with zero seepage. That's the most competent inspection I've ever gotten from a contractor.I'd recommend them to anyone dealing with the same problem."
"I bought a house in Kennett Square, PA knowing it had a moisture issue in the crawl space — previous owners had put down a thin plastic sheet that was doing nothing. Arrow Tight Waterproofing encapsulated the entire crawl space with a 20-mil liner, sealed the vents, and installed a dehumidifier. Within two weeks my downstairs floors stopped feeling cold and damp and the musty smell completely disappeared. The technician walked me through every step before starting. No surprises on the invoice.That kind of result speaks for itself."
"We had a window well that flooded every time we got more than an inch of rain. The well was filling up and water was coming straight in through the window sill joint. The fix was a regraded well with a perforated pipe tied into our existing interior drain. The whole job took one day. The crew was professional, cleaned up completely, and the well has handled every storm since without an issue.I'd recommend them to anyone dealing with the same problem."
"Called Arrow Tight Waterproofing after my old sump pump failed during a storm and I had 4 inches of water on my basement floor. They answered at midnight, arrived within an hour, and had a temporary pump running within 20 minutes of showing up. Once the emergency was managed, they walked me through a permanent drainage system upgrade. That was 8 months ago — I've had 6 rain events including one significant storm and the basement has stayed dry.I'd recommend them to anyone dealing with the same problem."
"As a commercial property manager overseeing several buildings in Kennett Square, PA, I've worked with a lot of waterproofing contractors. Arrow Tight Waterproofing is the first one that showed up to the initial walk with a written inspection checklist and completed it on-site before quoting. Every other contractor just eyeballed it and sent a number. Their exterior membrane on the building we had done 3 years ago is holding perfectly with zero callbacks.I'd recommend them to anyone dealing with the same problem."

We've built our service infrastructure in PA around regional crew staging rather than a single central office — which means your technician is driving 20 minutes to your property, not two hours. Coverage covers urban cores, suburban communities, and rural properties throughout Kennett Square, PA.
For property owners in Kennett Square and the surrounding areas, same-day or next-day appointments are typically available. Emergency calls — active flooding, sump pump failure, sudden seepage — receive priority routing and a 60-minute response target in most of our coverage footprint.
📞 Confirm Your Address is Covered — Call +1-866-476-1348