If your yard holds water, your patio is shifting, or you're planning a hardscape project, the answer usually starts underground. Here's what you need to know.
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If your yard stays wet long after the rain stops, or your patio has started to sink and shift, or you’re planning a retaining wall or outdoor kitchen and wondering what actually goes into it, you’re in the right place. These aren’t unusual problems, and they’re not random. In Delaware County, they almost always come back to the same thing: what’s happening underground. This page is here to answer the questions most contractors never bother to explain, specifically what excavation really means, why drainage can’t be an afterthought, and what it takes to get a hardscape project that actually holds up for the long run.
Excavation is more than digging a hole. It’s the process of removing soil, vegetation, old pavement, and other material to a precise depth: one that’s calculated based on what’s being built, how the site drains, and what the soil beneath it is doing. For a patio, that means excavating deep enough to install a compacted base layer that won’t shift or hold water. For a retaining wall or foundation, it goes deeper still, with grading and drainage built into the design from the start.
What separates professional excavation from a guy with a shovel is the process behind it. We assess soil before a single cut is made. Utility lines get located: Pennsylvania law requires contractors to call 811 before any excavation, and we follow that standard every time. Base materials go in and get compacted in layers, not dumped and smoothed over. And the finished grade is set so water moves away from your home and hardscape, not toward it.
Delaware County sits on some of the most drainage-challenging soil in the region. The heavy clay that runs through communities like Havertown, Springfield, Aston, and Glen Mills doesn’t absorb water the way sandy or loamy soil does. Instead, it holds it, pooling around foundations, collecting beneath hardscape bases, and building up the kind of hydrostatic pressure that can crack walls and heave patios over time.
There’s a pattern that shows up constantly in older Delco neighborhoods. When a home is built, the contractor excavates for the foundation, builds it up, and backfills the surrounding area with looser soil. Over the years, that loose backfill settles into a natural bowl shape right around the foundation, and every time it rains, that bowl fills up. It’s the same dynamic that plays out under a poorly prepared patio base. Water finds the low spot, sits there, and starts doing damage that you won’t see until it’s already expensive.
This is why excavation in Delaware County isn’t just about depth: it’s about drainage design. A base layer installed without accounting for how clay soil behaves is a base layer that’s already working against you. The excavation has to be deep enough, the compaction has to be done right, and the grading has to direct water somewhere it can actually go. When all three of those things happen together, the project holds up. When any one of them gets skipped, you’re usually looking at a repair bill within a few years.
Pennsylvania winters add another layer to this. Freeze-thaw cycles hit Delaware County hard every year. Water that infiltrates an improperly prepared base freezes, expands, and physically pushes the surface upward. Pavers shift. Retaining walls crack. Walkways buckle. The homeowner sees the surface problem and assumes it’s a materials issue or poor installation, but the real cause was underground, and it was preventable.
Excavation and drainage aren’t two separate services; they’re the same conversation. When we excavate a site, we’re not just preparing a base. We’re also making decisions about how water is going to move across and through that property for the next several decades. Those decisions get made during excavation, not after the fact.
If your yard has standing water after rain, the fix usually isn’t a surface-level patch. It’s a drainage system, such as a French drain, a catch basin, or a properly graded swale, installed at the right depth and connected to an outlet that actually works. That work requires excavation. And if you’re already excavating for a patio or retaining wall, the time to integrate drainage is during that process, not after the pavers are set and the wall is built.
Drainage problems are common throughout Delaware County, and they tend to get worse in communities with older housing stock. Homes in Broomall, Newtown Square, and Havertown that were built in the 1950s and 60s often have drainage systems designed for smaller storm events, and those systems are regularly overwhelmed now. When spring flooding hits lower-lying areas like Glen Mills, it’s rarely a surprise to the homeowners there. What surprises them is finding out that a properly graded yard with a functioning drainage system could have prevented most of it.
We also see this play out on the hardscape side. Retaining walls that are leaning or cracking are almost always a drainage problem at the root. Water builds up behind the wall, the pressure mounts, and eventually the structure moves. A masonry patch doesn’t solve that; addressing the drainage behind the wall does. The same applies to patios that pool water at one end or develop soft spots underneath. These aren’t cosmetic issues. They’re drainage issues that started during excavation.
Most homeowners don’t come to us already knowing what they need. They come with a symptom (a wet yard, a shifting patio, or a project they want to start) and they have questions. Good questions. The kind that don’t always get answered clearly by contractors who are in a hurry to give you a number and move on.
Here are the ones we hear most often, answered as plainly as we can.
It depends on the scope and the municipality. Delaware County is made up of 49 separate townships and boroughs, each with its own code requirements. Generally speaking, excavation for a residential patio or retaining wall under a certain height won’t require a permit in most townships, but grading work that affects stormwater runoff, excavation near a property line, or any work that involves utility connections typically does.
The honest answer is that you shouldn’t assume either way. We check permit requirements for your specific address and municipality before proposing any work. A contractor who waves the question off is one worth being cautious about. Unpermitted work can create real problems when you go to sell your home or file an insurance claim, and the homeowner, not the contractor, is usually the one left holding that.
We handle permit questions as part of the project planning process. If your project in Springfield, Aston, or anywhere else in Delaware County requires a permit, we’ll tell you before work starts, not after.
The most important thing you can verify is licensure. Pennsylvania requires contractors performing home improvement work to hold an active Home Improvement Contractor registration. We hold a verified active PA contractor license and rank in the top 11% of over 125,000 licensed Pennsylvania contractors per BuildZoom’s scoring system. That’s not a marketing claim; it’s a verifiable number.
Beyond licensure, ask about the process. How deep are we excavating, and why? How are we compacting the base? What happens if we hit rock, a root system, or an unexpected utility? These aren’t trick questions: a contractor with experience in Delaware County’s clay soil will have clear, straightforward answers.
Ask about drainage specifically. Even if you’re calling about a patio or retaining wall, ask how we’re handling water. In Delco’s clay soil, that question is never irrelevant.
Also ask whether we’re calling 811 before breaking ground. Pennsylvania law requires it. It locates underground utility lines before any digging starts, protecting you from gas line strikes, water main damage, and the liability that comes with them. It’s a basic professional standard. Its importance becomes clear when looking at the whole construction timeline. Regardless of the project type, you get one experienced team from start to finish, not a rotating cast of subcontractors. When the excavation crew and the hardscape crew are the same people, there’s no gap between what was dug and what gets built on top of it. No finger-pointing if something doesn’t look right. One call, one team, one finished project.
If there’s one thing worth taking from this page, it’s that the work happening underground determines everything you see above it. A patio that holds up for twenty years and one that needs to be torn out in five are often separated by what happened during excavation: the depth, the compaction, and the drainage integration.
Delaware County’s clay soil, its freeze-thaw winters, and its aging housing stock make getting this right more important here than in a lot of other markets. The problems are real, they’re common, and they’re preventable when the foundation work is done correctly from the start. If you have a project in mind, or a problem you’re trying to understand before it gets worse, we offer free initial consultations and will give you a straight answer about what your property actually needs. Reach out and let’s figure out the right starting point together.
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