Formula
Bulk sand and bedding sand are the plan area times the depth. Waste multiplies that volume. Tons are the order yards times the pounds per yard, divided by 2,000. Bags are the order cubic feet divided by the bag size, rounded up. A second area is added before the waste.
yards = (area × depth in feet) × (1 + waste ÷ 100) ÷ 27
module = (paver length + joint) × (paver width + joint)
joint fraction = (module − length × width) ÷ module
joint ft³ = area × 144 × fraction × fill depth ÷ 1,728
pounds = joint ft³ × lb/ft³ × (1 + waste ÷ 100)
A 10 × 12 ft sandbox, 2 in deep, no waste, at 2,700 lb/yd³ is 20 ft³, 0.741 yd³, 1 ton, and 40 bags of 0.5 ft³. Two hundred square feet of 1 in bedding with 10% waste is 0.679 yd³ and 37 bags. The 1 inch layer is screeded over a compacted base. Concrete sand meeting ASTM C33 is the bedding gradation in CMHA installation guidance. Stone dust and fine play sand are not that sand.
Polymeric sand fills the joint, not the bed. For 200 ft² of 4 × 8 in pavers, 2⅜ in thick, with a ⅛ in joint filled full depth at 100 lb/ft³, the joint is about 1.79 ft³. At 10% waste that is about 196.9 lb, still 4 bags of 50 lb. Joints wider than about 1 inch belong to a wide-joint product. Sweep polymeric sand into dry joints, compact, and mist the way the bag says. The chart printed on that bag takes precedence over this estimate.
Worked examples
10 × 12 ft, 2 in, 0% waste, 2,700 lb/yd³. 20.0 ft³, 0.741 yd³, 1.00 ton, 40 bags.
200 ft² bedding, 1 in, 10% waste. 18.333 ft³, 0.679 yd³, 0.917 tons, 37 bags.
200 ft² of 4 × 8 pavers, ⅛ in joints, 2⅜ in fill, 10% waste. About 1.79 ft³ and 197 lb, 4 bags. At 0% waste the same patio is about 179 lb, still 4 bags.
100 ft² of 12 × 12 pavers, ¼ in joints, 0% waste. About 0.800 ft³ and 80 lb, 2 bags.
Reference
Dry sand at 2,700 lb/yd³ is 1.35 ton/yd³. Damp sand at 3,200 lb/yd³ is 1.60 ton/yd³. Fifty-four bags of 0.5 ft³ fill one cubic yard. Polymeric defaults are 100 lb/ft³ and a 50 lb bag.
Questions
How much sand do I need for pavers?
A screeded bedding layer is usually 1 inch of concrete sand over a compacted base. Two hundred square feet at 1 inch, plus 10% waste, is about 0.679 cubic yards, or 37 bags of 0.5 cubic feet. The base under that sand is a gravel order, not more sand.
How many bags of polymeric sand for 100 square feet?
It depends on the paver and the joint. One hundred square feet of 12×12 pavers with a ¼ inch joint, filled 2⅜ inches deep at 100 lb/ft³, is about 80 pounds, or 2 bags of 50 pounds, before waste. A 4×8 with a ⅛ inch joint uses more joint per square foot. The chart on the bag wins.
How much does a yard of sand weigh?
This page uses 2,700 lb, about 1.35 tons, for dry sand, and 3,200 lb, about 1.60 tons, for damp sand. Grading and moisture move both. Ask the yard.
How many 50 lb bags of sand are in a yard?
A 0.5 cubic foot bag is the usual 50 lb play or all-purpose bag. 27 ÷ 0.5 is 54 bags in a cubic yard of that size. Weight still depends on moisture, so 54 bags are not automatically 2,700 pounds.
How thick should sand be under pavers?
The usual screeded bedding layer is 1 inch, and this page allows ¾ to 1½ inches. It sits on a compacted aggregate base. It is not the base itself.
What kind of sand goes under pavers?
Concrete sand, the coarse sand described by ASTM C33, is the bedding sand in CMHA installation guidance. Stone dust and fine play sand are a different gradation. Play sand is for a sandbox, not for a paver bed.
Can I use play sand for pavers?
Not as bedding. Play sand is fine. Paver bedding wants the coarser concrete-sand gradation. For the sandbox itself, buy sand sold as play sand. This page does not rank sand for health.
Sources
- Concrete Masonry & Hardscapes Association, formerly the Interlocking Concrete Pavement Institute. Installation guidance for interlocking concrete pavement calls for a screeded bedding layer about 1 inch thick of concrete sand, not stone dust. This page keeps that depth editable from ¾ to 1½ inches.
- ASTM C33, concrete aggregates. That is the concrete-sand gradation cited for paver bedding. This page does not reprint the sieve table.
- Loose sand weights of 2,700 and 3,200 lb/yd³ are planning figures. Published material tables put dry and damp sand in that neighborhood. The yard ticket is the weight.
- The polymeric formula is the joint fraction of the paver module. It is an estimate. The coverage chart on the bag takes precedence. The base under the bedding sand is the gravel calculator.