Hear from Our Customers
You stop worrying every time it rains. You stop checking the basement after every storm. You stop wondering if that musty smell means mold is growing behind your walls.
When your basement is properly waterproofed, you get your space back. You can finish it, store things in it, or just ignore it without anxiety. Your home value stays protected because buyers won’t walk away after a home inspection finds moisture problems.
The health stuff matters too. Mold and mildew from basement moisture cause respiratory issues, especially in kids. When you fix the water problem, you fix the air quality problem. Your family breathes easier, literally.
Most importantly, you avoid the nightmare scenario. The one where you’re looking at $5,000+ in water damage restoration, ruined belongings, and structural repairs that could’ve been prevented. Waterproofing isn’t just about keeping things dry—it’s about protecting what you’ve built.
Del Val Basement Waterproofing is a family-run waterproofing contractor serving King of Prussia and the surrounding Pennsylvania counties. We’ve spent over 15 years solving the same problems you’re dealing with right now.
King of Prussia sits in an area where clay soil and older home construction create perfect conditions for basement water problems. The clay bowl effect—where excavated soil around your foundation absorbs more water than undisturbed soil—puts constant pressure on basement walls. We see it every day.
We’re not the biggest waterproofing company in King of Prussia, PA. We’re the one that shows up, diagnoses your specific problem correctly, and installs systems that actually work long-term. Our lifetime transferable warranty backs that up.
First, we come out and inspect your basement. We’re looking for where water’s getting in, what’s causing the pressure, and whether you need interior, exterior, or both. You get a free estimate that breaks down exactly what we found and what we recommend.
If you move forward, we schedule the work around your life. Most interior waterproofing jobs don’t require you to leave your home. We install our Sub Floor Pressure Relief System—a more effective alternative to traditional French drains that structural engineers actually recommend. It relieves hydrostatic pressure before it can push water through your walls.
For exterior work, we excavate around the foundation, apply waterproof membrane, install proper drainage, and backfill correctly. It’s more invasive but it stops water at the source.
Once we’re done, we test everything, clean up, and walk you through what we did. Then you wait for the next rainstorm. That’s when you’ll see the difference—when your basement stays dry and you don’t have to think about it anymore.
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You get a complete assessment of your water problem, not just a sales pitch. We identify whether you’re dealing with surface water, groundwater, hydrostatic pressure, or foundation cracks. Each one requires a different solution.
Interior waterproofing includes our Sub Floor Pressure Relief System, sump pump installation if needed, and sealing of any cracks or gaps. This approach works for most King of Prussia homes and costs significantly less than exterior excavation. It’s designed to last for the life of your home with minimal maintenance.
Exterior waterproofing means we dig down to your footer, apply waterproof coating, install drainage systems, and ensure water moves away from your foundation. This is the most thorough approach and makes sense if you’re already dealing with foundation issues or if interior methods won’t solve your specific problem.
You also get our lifetime transferable warranty. If you sell your home, the warranty transfers to the new owner. That’s a selling point that actually matters during negotiations.
King of Prussia’s weather patterns—heavy spring rains, summer thunderstorms, winter freeze-thaw cycles—put constant stress on basement waterproofing systems. We account for that in every installation. You’re not getting a one-size-fits-all solution. You’re getting what actually works in this area.
Interior waterproofing typically runs between $3,000 and $7,000 depending on your basement size and the severity of your water problem. That includes the drainage system, sump pump if needed, and labor.
Exterior waterproofing costs more—usually $8,000 to $15,000—because we’re excavating around your foundation. But if you’re already dealing with foundation cracks or severe water intrusion, exterior work might be the only permanent fix.
Here’s the reality: water damage restoration after a flood costs between $1,300 and $6,000. And that’s just cleanup—it doesn’t fix the underlying problem. You’ll pay that again next time it rains hard. Waterproofing is cheaper than repeatedly fixing water damage, and it protects your home value long-term.
Interior waterproofing manages water after it’s already entered your foundation walls. We install drainage systems inside your basement that collect water and redirect it to a sump pump, which pumps it away from your home. It’s less invasive, costs less, and works well for most situations.
Exterior waterproofing stops water before it reaches your foundation. We excavate around your home, apply waterproof membrane to the outside of your foundation walls, install drainage systems at the footer level, and ensure proper grading. This is the most comprehensive approach but requires more work.
Most King of Prussia homes do fine with interior waterproofing. We recommend exterior work when you have significant foundation cracks, when interior methods have failed, or when you’re already excavating for foundation repairs. Sometimes you need both—interior drainage as a backup system even after exterior waterproofing.
Our Sub Floor Pressure Relief System lasts for decades with minimal maintenance. The drainage channels don’t clog like old French drains because they’re designed differently. Sump pumps typically last 7-10 years, but they’re easy to replace when needed.
Exterior waterproofing membrane can last 50+ years if installed correctly. The key is proper installation and ensuring water drains away from your foundation rather than pooling against it.
That’s why we offer a lifetime transferable warranty on our work. We’re not expecting callbacks. The systems we install are designed to outlast your ownership of the home. Most waterproofing failures happen because the original work was done incorrectly or because the wrong solution was used for the specific problem. When you diagnose correctly and install properly, waterproofing becomes a one-time fix.
Waterproofing eliminates the moisture that mold needs to grow. No moisture, no mold. But if you already have mold, waterproofing alone won’t remove it—you’ll need mold remediation first.
Here’s what happens: basement moisture creates humidity levels above 60%, which is where mold thrives. Mold spores are always present in the air, but they only become a problem when they find moisture and organic material to feed on. Drywall, wood, cardboard boxes—all perfect mold food when wet.
Once we waterproof your basement and install proper drainage, humidity levels drop. The space dries out. Existing mold stops spreading and new mold can’t establish itself. If you have visible mold now, we can handle remediation as part of the project. But the waterproofing is what prevents it from coming back. You can’t just kill mold and hope it stays gone if you don’t fix the moisture problem.
Most interior waterproofing systems require a sump pump to move collected water away from your home. The drainage system channels water to a sump pit, and the pump pushes it outside to a safe discharge point.
If your basement is on a slope and gravity can move water away naturally, you might not need a pump. But in King of Prussia, most properties don’t have enough grade for gravity drainage to work reliably. A sump pump is your insurance policy.
We typically install primary pumps with battery backup systems. When heavy storms knock out power—exactly when you need your pump most—the battery backup keeps running. It’s an extra cost upfront but it prevents the nightmare scenario where your pump stops working during a flood. You can also consider a water-powered backup pump that runs off your home’s water pressure if the primary pump fails.
You can apply waterproof paint or sealant yourself. It might help with minor dampness. But if you’re dealing with actual water intrusion, standing water, or foundation cracks, DIY solutions won’t fix the problem. They’ll just delay it.
Proper waterproofing requires diagnosing the source of water, understanding hydrostatic pressure, installing drainage systems correctly, and ensuring water moves away from your foundation permanently. Most homeowners don’t have the equipment or experience to do this right. We see a lot of failed DIY attempts that end up costing more to fix than if they’d called a waterproofing contractor from the start.
The bigger issue is liability. If you install a system incorrectly and it fails, you’re paying for water damage restoration and trying again. When we install it, you get a lifetime warranty. If something goes wrong, we fix it. That peace of mind is worth hiring a professional basement water damage repair company that knows what they’re doing.
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