How Much Limestone Screenings for a 20x18 Patio?
How much limestone screenings for a 20x18 patio: at 3 inches deep you need about 3.33 cubic yards, which is roughly 4.7 tons at 1.4 tons per yard. The patio covers 360 square feet, so every inch of depth adds about 1.11 yards.
Volume and tonnage calculator →The math for a 20x18 patio
- Area: 20 × 18 = 360 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 360 × 0.250 = 90.0 cu ft.
- Cubic yards: ÷ 27 = 3.33 yd³.
- Tons: × 1.4 = 4.7 tons.
The volume and tonnage calculator does this for any size.
Limestone screenings needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 1 in | 1.11 | 1.6 | 1.7 |
| 2 in | 2.22 | 3.1 | 3.4 |
| 3 in | 3.33 | 4.7 | 5.1 |
About limestone screenings
Limestone screenings are the fine dust and chips left after crushing limestone. They pack very tight, which makes them a common setting bed for pavers and flagstone and a surface for paths. 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. 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. 5.1 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.
Where limestone screenings fits
Good uses:
- Paver and flagstone setting beds
- Firm walking paths
- Top-dressing a compacted stone base
Think twice for:
- Deep layers on their own
- Low spots that collect water
- Under heavy vehicle traffic without a base
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of limestone screenings (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 12x24 area at 3 inches takes about 3.7 tons.
- Weight used here: about 1.4 tons per cubic yard.
Where estimates go wrong
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- 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.
Questions people ask
How many tons of limestone screenings for a 20x18 patio?
About 4.7 tons at 3 inches deep, or 5.1 tons with 10 percent extra.
How many cubic yards is a 20x18 patio at 3 inches?
About 3.33 cubic yards.
How much does a cubic yard of limestone screenings weigh?
Usually around 1.3 to 1.5 tons, depending on stone size, fines and moisture.
How deep should limestone screenings be for a patio?
The table above shows 1 to 3 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 20x18?
360 square feet.
Related guides
- #10 Stone (Stone Dust): Size, Uses and How Many Tons
- 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 Limestone Screenings for a 20x14 Patio?
- How Much Limestone Screenings for a 20x16 Patio?
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