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How Much Decomposed Granite for a 10x18 Patio?

How much decomposed granite for a 10x18 patio is a quick volume problem. 180 square feet at 3 inches comes to 1.67 cubic yards. Decomposed granite usually weighs about 1.25 to 1.45 tons per cubic yard, so plan on roughly 2.3 tons.

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The math for a 10x18 patio

  1. Area: 10 × 18 = 180 sq ft.
  2. Depth in feet: 3 ÷ 12 = 0.250 ft.
  3. Cubic feet: 180 × 0.250 = 45.0 cu ft.
  4. Cubic yards: ÷ 27 = 1.67 yd³.
  5. Tons: × 1.35 = 2.3 tons.

The volume and tonnage calculator does this for any size.

Decomposed granite needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in1.111.51.7
3 in1.672.32.5
4 in2.223.03.3

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. Weight per yard is a planning number; the scale ticket at the yard is the real one.

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. For foot traffic and furniture, the depths in the table above are a reasonable starting range.

Ordering tips

  • Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
  • Delivery size. 2.5 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

Think twice for:

  • 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 3 inches takes about 3.6 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.
  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
  • Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
  • Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.

Questions people ask

How many tons of decomposed granite for a 10x18 patio?

About 2.3 tons at 3 inches deep, or 2.5 tons with 10 percent extra.

How many cubic yards is a 10x18 patio at 3 inches?

About 1.67 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 10x18?

180 square feet.

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