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Bags of Decomposed Granite for a 8x16 Patio

How many bags of decomposed granite for a 8x16 patio: at 3 inches deep you need about 32.0 cubic feet, which is 64 bags of the common 0.5 cubic foot size. If your store sells decomposed granite in 50-pound bags instead, figure about 64 bags, since decomposed granite weighs roughly 100 pounds per cubic foot.

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Bag count by depth

DepthCubic feet0.5 cu ft bags50 lb bags (approx.)
1 in10.72222
2 in21.34343
3 in32.06464
4 in42.78686

How to figure it

  1. Area: 8 × 16 = 128 sq ft.
  2. Volume: 128 × (3 ÷ 12) = 32.0 cu ft.
  3. Bags: 32.0 ÷ 0.5 = 64 bags (round up).

Bags or bulk?

A cubic yard is 27 cubic feet, so 32.0 cubic feet is 1.19 yards, about 1.6 tons. Past about a yard, bulk is usually less work and often less money. Compare the bag price × 64 against a bulk quote for 1.8 tons delivered.

About decomposed granite

Decomposed granite (DG) is weathered granite broken into small particles and fines. It packs into a firm, natural-looking path surface, and stabilized versions include a binder.

Install tips for a patio

  • Dig and level. Remove sod and set the base slightly below the surrounding grade.
  • Edge it. Steel, plastic or stone edging keeps material in place.
  • Spread in layers. Rake to depth, then tamp or wet and compact.
  • Buy a few extra. Grab 5 to 10 percent more bags for settling and touch-ups.

The volume and tonnage calculator handles other sizes and depths.

Where decomposed granite fits

Good uses:

  • Garden paths and patios with a natural look
  • Around trees and in xeriscape designs
  • Stabilized DG for accessible paths

Poor fit 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 15x30 area at 3 inches takes about 5.6 tons.
  • Weight used here: about 1.35 tons per cubic yard.

Common estimating mistakes

  • Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
  • Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
  • 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.

Questions people ask

How many bags of decomposed granite for a 8x16 patio?

About 64 bags of 0.5 cubic feet at 3 inches deep.

How many 50 lb bags of decomposed granite for 8x16?

About 64 bags at 3 inches.

How many 0.5 cubic foot bags are in a cubic yard?

54 bags.

How many cubic feet is a 8x16 patio at 3 inches?

About 32.0 cubic feet.

When does bulk make more sense?

Usually once the job passes about a cubic yard, or when you would need more than a few car trips.

Related guides

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