Can I use gravel instead of road base?

No. Clean gravel (like river rock or drainage rock) lacks the 'fines' or stone dust required to lock the particles together. Clean gravel acts like a bag of marbles—it shifts under weight. You need compactable material like road base or decomposed granite with fines to create a solid floor.

How do I match the old pavers?

This is the hardest part of patching. If you don't have spares, check the side of the house or under a deck where pavers might have been laid but aren't visible. You can 'steal' those weathered pavers for the patch and replace the hidden ones with new, mismatched bricks. If that fails, take a sample to a landscape supply yard—big box stores often only carry modern stock.

Why did the dirt sink in the first place?

Soil is mostly air and organic material. When you dig it up, you 'fluff' it, introducing more air. Even if you stomp on it, it will settle over time as water percolates through. Furthermore, burying organic matter (like roots) creates a slow-motion sinkhole as that material decomposes and vanishes.

Don't Just Add Dirt: How to Patch a Paver Hole Without It Sinking

Before: A deep dirt hole next to a brick wall where pavers are missing. After: The hole is paved over flush, featuring a potted native shrub.

The Dilemma

A homeowner recently asked:

I just dug out a tree next to my foundation and want to pave over the hole to match the existing patio. Can I just fill the void with the dirt I removed, or do I need specific materials?

The GardenOwl Diagnosis

The Scenario

We see this all the time: a homeowner does the hard work of removing an ill-placed tree, only to fumble the finish line. In this case, a tree was (correctly) removed from a tight spot directly against a brick foundation and a crawlspace access door. Now, there is a gaping void in the patio.

The homeowner is ready to patch it up and asks the classic DIY question: "Can I just fill this back in with the dirt I dug out?"

This is a textbook case of Substrate Denial Syndrome. It is the belief that the surface finish (the pavers) is the structural element, when in reality, the pavers are just a skin. The real work happens underneath. If you skip the sub-base here, you aren't fixing the patio; you are building a future sinkhole.

The Trap

Dirt is not a building material; it is a living medium. The soil you just excavated—and the soil left behind in that hole—is full of organic matter, chopped roots, and air pockets.

If you shovel that loose dirt back into the hole and lay bricks on top, two things will happen:

Decomposition: The organic matter (roots, leaves, mulch) in the soil will rot over time. As it rots, it loses volume.
Settling: Loose soil consolidates when water hits it.

Within six months, that patch will slump 2-3 inches below the rest of the patio. This creates a trip hazard and, more dangerously, a depression that collects water right against your foundation wall. Since this is right next to a sub-floor access point, that water will find its way under your house.

The Solution: Structural Fill

You have done the demolition; now you need to do the engineering. You are not gardening here; you are road-building on a micro scale. Here is the step-by-step fix to ensure that patch never moves.

1. Excavate to the Correct Depth

Don't start filling yet. You need to dig down 150mm to 200mm (6-8 inches) below the bottom of your existing pavers. You need to get past the fluffy topsoil to relatively undisturbed subsoil.

2. The Road Base (The Muscle)

Go to the hardware store (Bunnings, for our Aussie friends) and buy bags of "Road Base". This is a mix of crushed rock (usually 20mm aggregate) and "fines" (stone dust).

Why it works: The jagged rocks lock together for strength, and the dust fills the voids to prevent movement.
Installation: Pour it in layers (lifts) of about 50mm at a time. Do not dump it all at once.

3. Moisture and Violence

This is the most critical step. Lightly mist the road base with a hose—you want it damp, not soupy. Then, tamp it down.

For a small patch like this, buy a hand tamper (a heavy steel plate on a stick). Pounding it with a piece of wood isn't enough. You need to compress that rock until it feels like concrete. If you jump on it and leave a footprint, you aren't done.

4. The Bedding Layer

Once your road base is rock-hard and sits about 30-40mm below the bottom of the existing pavers, add a layer of coarse bedding sand (washed river sand).

The Rule: This layer is for leveling, not structure. Keep it to 25mm (1 inch) thick. Do not compact this yet.

5. Lock it In

Place your pavers on the sand. Use a rubber mallet to tap them level with the surrounding bricks. Once they are in, sweep fine jointing sand into the cracks to lock them together.

6. Soften the Hardscape

The homeowner mentioned putting plants back. Do not plant in the ground here. The tree was removed for a reason—roots damage foundations. Instead, place a large, glazed pot on your new stable surface. A native choice like a Dwarf Banksia or Grevillea is perfect. It provides the greenery you want without the root invasion you just spent all weekend fixing.

The Diagnostic Safety Net

Before you swing a mattock near your foundation, it helps to know what you're looking at. GardenDream isn't just for pretty pictures; it acts as a diagnostic safety net. You can upload a photo of your problem area, and it helps you visualize structural constraints—like drainage slopes and foundation setbacks—so you don't accidentally design a water trap. It’s cheaper to simulate the repair digitally than to fix a flooded crawlspace later.