What it is
Coarse concrete sand (ASTM C-33 spec) sold by the ton. This is the 1-inch bedding course that goes between the compacted base and the pavers or flagstone. Don't confuse this with polymeric joint sand (different product, different job) or play sand (wrong grain shape — pavers will wobble on play sand).
What it's for
Every paver and flagstone install needs three layers: compacted crushed-limestone base, then a 1-inch leveling course of this concrete sand, then the stone on top. The sand layer is what lets you screed a perfectly flat surface for the stones to sit on. Skip it and your patio will be a Frankenstein of high and low pieces no matter how perfect your base is.
Standard installs:
- Paver patios — 1" bedding course
- Flagstone patios — 1" bedding course (the irregular bottom of flagstone needs the sand to settle into)
- Paver driveways — 1" bedding course over a 6" compacted limestone base
- Bluestone steppers — 2" bedding course (steppers are heavier per piece, deeper bed helps)
How much do I need
At a 1-inch bed:
| Patio size | Tons of sand |
|---|---|
| 100 sq ft | 0.4 |
| 200 sq ft | 0.85 |
| 400 sq ft | 1.7 |
| 800 sq ft | 3.4 |
| 1,500 sq ft | 6.5 |
The flagstone patio wizard and paver patio wizard compute the sand course for you. We round up to whole tons.
Why concrete sand, not mason or play sand
Concrete sand (also called ASTM C-33) has sharp, angular grains that lock together when compacted. Mason sand is finer and rounder — it works for mortar but pavers settle into it unevenly. Play sand is too soft and fine for any structural application.
If a contractor offers to put your pavers down on mason sand to save a few bucks, that's a red flag.
How to install it
- Compact your base course to spec (typically 4-6" of 1" crushed limestone, compacted in 2" lifts).
- Set 1-inch screed rails along the run.
- Dump concrete sand between the rails, screed it flat with a 2x4.
- Remove rails, fill the void with sand, smooth.
- Lay your pavers or flagstone on the prepared bed. Don't walk on the screeded sand before the stones go down.
- Compact pavers with a plate compactor (use a rubber pad to protect the surface). Don't compact flagstone — set by hand.
Buying tips
- Delivered loose by the ton. Plan a tarped pile near the install — keep it dry.
- For driveways, double the bed depth (2") if you're going to drive trucks on it during install.
- Don't over-order. Sand left over after an install gets contaminated fast outside.
Contractor notes
Volume pricing at 5 tons. Combo deliveries available — drop sand and crushed limestone on the same truck for the base + bed quote.