Almost every sunken, wavy, weed-infested patio you've seen failed for the same reason: the base was too thin, wasn't compacted, or used the wrong sand. The pavers are the easy part. Here's how to get the part underneath right.
The three layers
| Layer | Material | Depth |
|---|---|---|
| Base | Crushed gravel / crusher run | 4–6 in (patio), 8–12 in (driveway) |
| Bedding | Coarse concrete sand | 1 in — exactly |
| Surface | Pavers | Their own thickness |
Each layer does a different job. The gravel spreads load and drains water away. The sand is a thin levelling bed. The pavers take the wear. Skip or thin any layer and the whole thing moves.
Why the gravel has to be crushed
Use crushed stone, not rounded pea gravel or river rock. Crushed stone has sharp, angular faces that lock together under compaction and stay locked. Rounded stone rolls — it can't interlock, so it shifts under load no matter how hard you tamp it.
Crusher run (crushed stone mixed with stone dust) is the usual choice because the fines fill the voids and it compacts to something close to solid. Our crushed stone calculator converts your area and depth into cubic yards and tons, and the gravel calculator does the same for standard gravel.
The bedding sand rule people break
One inch. Not two, not three, not "however much it takes to level things out."
This is the mistake that ruins otherwise good patios. Sand doesn't compact meaningfully — it's a bedding layer, not a base. Every extra inch is another inch that can shift, rut, and wash out. If your gravel is uneven, the fix is fixing the gravel, not burying the problem in sand.
Use coarse concrete sand, sometimes called C-33 or bedding sand. Not play sand — the grains are too fine and round, and it holds water and moves. Not mason's sand either. The sand calculator works out the volume for a 1-inch layer.
Screed it flat with a straightedge over pipe rails, then don't walk on it. Footprints in screeded sand become dips in the finished patio.
Slope it, always
A patio must shed water away from the house — about 1/4 inch of drop per foot, so roughly 2 inches over an 8-foot patio. It's imperceptible to walk on and it's the difference between a dry patio and a puddle against your foundation.
Build the slope into the gravel base, not the sand. The sand layer stays a uniform inch throughout; the grade underneath does the work.
Edge restraints are not optional
Without an edge restraint, the perimeter pavers creep outward, the joints open, and the whole field loosens from the outside in. Plastic paver edging staked into the compacted base is cheap and it's the difference between a patio that holds its shape for 20 years and one that spreads in five.
How much to order
Work out square footage, then run the depths through the calculators — and add about 10%. Gravel compacts by roughly 20% as you tamp it, which means the 4 inches you spread is not the 4 inches you end up with. Order for the compacted depth, not the loose one.
Once your base is in, the paver calculator gives you paver counts including cutting waste.
Try the free calculator
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Frequently Asked Questions
How deep should a paver base be?
Four to six inches of compacted crushed gravel for a patio, and eight to twelve inches for a driveway, plus exactly one inch of bedding sand on top.
How much sand goes under pavers?
Exactly one inch of coarse concrete sand. More sand is the most common cause of patios that rut and sink, because sand doesn't compact the way gravel does.
What kind of gravel goes under pavers?
Crushed stone or crusher run, never rounded pea gravel. Angular crushed stone locks together under compaction, while rounded stone rolls and shifts under load.
Why is my paver patio sinking?
Almost always an inadequate base — too thin, not compacted in layers, or too much bedding sand. Compact gravel in 2-inch lifts and keep the sand to one inch.