Why We Only Use Open-Graded Base for Paver Installations (And Why You’ll Be Glad We Do)

Jonathan Garcia
Jun 24
3 min read

When it comes to building a long-lasting paver patio, driveway, or walkway, what you see—the beautiful pavers, the clean lines, the border work—is only part of the story. The real magic (and structural integrity) happens underneath.

At G Construction & Landscape, we follow the industry’s best practices using ICPI-certified installation methods and only Unilock-approved base systems. That means we only use open-graded base construction for every single one of our paver installs. Period.

If you've never heard of open-graded vs dense-graded base—don't worry. You're not alone. But once you understand the difference, you'll see exactly why this matters and why cutting corners below the surface can cost thousands down the road.

Dense-Graded Base (The Old School Way)

Dense-graded base (also called “compacted base” or "CA6 base" around here) is made up of crushed stone with fine particles—or “fines”—mixed in. It’s been used for decades and does a decent job of locking together when compacted.

But here’s the problem:

It doesn’t drain well.

The fines in dense-grade make it almost impermeable. So when water gets underneath your pavers—either from rain, snowmelt, or improper slope—it has nowhere to go. Over time, water builds up, freezes, thaws, and shifts the base… and that leads to:

Heaving and settling
Wavy pavers and trip hazards
Stains from trapped moisture
Weed growth in joints
And worst of all—a patio that looks 10 years old after just 2

Open-Graded Base (What the Pros Use Now)

Open-graded base, on the other hand, uses clean, angular stone with little to no fines—usually a combination of ¾" clear gravel (CA7) and 3/8" chip stone for bedding. Think of it like a system of interlocking stones with built-in drainage.

Why is that important?

Because water is always going to find its way in. We just give it a way out.

Here’s why open-graded systems are now considered the ICPI industry standard (and why we’ve been using them exclusively):

✅ Superior Drainage:Open-graded bases allow water to flow straight through instead of pooling. That means no freeze-thaw shifting and a significantly longer lifespan for your patio or driveway.

✅ Stronger Load Capacity:Properly compacted angular stone offers excellent interlock, giving your base superior strength and reducing movement under heavy loads (great for driveways, too).

✅ Cleaner Install, Cleaner Results:No fines means less dust during install, and no dirty runoff later staining your pavers or making a mess.

✅ Eco-FriendlyPair it with permeable pavers, and you're helping reduce stormwater runoff—a win for your home and the environment.

✅ Less Maintenance Over TimeFewer drainage issues mean fewer repairs, joint failures, or do-overs. It's built to last, and it stays that way.

But Does It Cost More?

A little. Not a lot. And it’s money well spent.

The extra investment in material and labor (about 10–15% more up front) pays off big time in the long run. You’re getting a cleaner, stronger, and more resilient patio or driveway—with less risk of failure.

Our Process – Built the Right Way, Every Time

Here’s how we typically build your paver project with an open-graded base:

Excavation to proper depth, based on soil conditions and final use (typically 10–12" for patios, 14–18" for driveways).
Non-Woven Geotextile Fabric installed to separate base from native soil and prevent migration.
Base Layer: ¾" angular clean gravel (CA7) compacted in 3" lifts.
Bedding Layer: 3/8" chip stone (ASTM #8) for perfect paver setting.
Paver Installation using Unilock products with tight joint tolerances.
High Performance Polymeric Sand (or permeable joint sand for permeable systems).
Concrete Edge Restraint – never plastic edge! We use concrete edge-crete for permanent structural restraint.

We build everything to ICPI and Unilock standards so your project doesn't just look good—it performs like it should for decades.

Putting Drainage First Is Putting You First

When we prioritize drainage from day one, we’re putting your long-term investment first. We don't believe in shortcuts. Every patio, walkway, and driveway we install is a reflection of our commitment to quality, durability, and integrity.

That’s why we say:The base is everything. And we only build on the best.

See It for Yourself

Take a look at some of our recent projects using open-graded base systems:

Thinking About a New Patio or Driveway? Let’s Talk.

If you're ready for a paver project that's built to last—and built the right way from the ground up—reach out to us for a free consultation.

We’ll walk your property, explain your options, and show you exactly how we deliver high-performance, low-maintenance outdoor living spaces across Downers Grove, Hinsdale, Naperville, and beyond.