How Much Decomposed Granite for a 8x20 Patio?
How much decomposed granite for a 8x20 patio: at 3 inches deep you need about 1.48 cubic yards, which is roughly 2.0 tons at 1.35 tons per yard. The patio covers 160 square feet, so every inch of depth adds about 0.49 yards.
Volume and tonnage calculator →The math for a 8x20 patio
- Area: 8 × 20 = 160 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 160 × 0.250 = 40.0 cu ft.
- Cubic yards: ÷ 27 = 1.48 yd³.
- Tons: × 1.35 = 2.0 tons.
The volume and tonnage calculator does this for any size.
Decomposed granite needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 0.99 | 1.3 | 1.5 |
| 3 in | 1.48 | 2.0 | 2.2 |
| 4 in | 1.98 | 2.7 | 2.9 |
About decomposed granite
DG should be laid in thin lifts, wetted and compacted. Loose DG at a deep depth stays soft and tracks onto shoes. If the yard sells by the cubic yard instead of the ton, use the cubic-yard column directly.
Preparing the patio
Remove sod, level the area with a slight slope away from the house, and lay landscape fabric if weeds are a concern. Edging keeps loose material inside the patio footprint. Since the patio carries foot traffic and furniture, a little extra depth is cheap insurance.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 2.2 tons fits in a single typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
- Bulk vs bags. At this size bulk delivery is usually the practical choice.
- Where it drops. Have the truck dump as close to the patio as firm ground allows.
Good and poor uses for decomposed granite
Good uses:
- Garden paths and patios with a natural look
- Around trees and in xeriscape designs
- Stabilized DG for accessible paths
Less suited to:
- Steep grades without a stabilizer
- Areas right outside doors, since fines track in
- Driveways with heavy turning traffic
Quick reference numbers
- Per inch over 100 sq ft: about 0.42 tons of decomposed granite (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.2 tons.
- Another size for comparison: a 12x24 area at 2 inches takes about 2.4 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
Questions people ask
How many tons of decomposed granite for a 8x20 patio?
About 2.0 tons at 3 inches deep, or 2.2 tons with 10 percent extra.
How many cubic yards is a 8x20 patio at 3 inches?
About 1.48 cubic yards.
How much does a cubic yard of decomposed granite weigh?
Usually around 1.25 to 1.45 tons, depending on stone size, fines and moisture.
How deep should decomposed granite be for a patio?
The table above shows 2 to 4 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 8x20?
160 square feet.
Related guides
- Crushed Stone vs Gravel: Differences and Best Uses
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much Decomposed Granite for a 8x16 Patio?
- How Much Decomposed Granite for a 8x18 Patio?
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