Washed Sand: The Coarse One, and What It Is For

Two sands sit next to each other on this site, and the difference decides jobs from a Gulf coast trench to a frost-belt patio. Washed sand is the coarse one: gritty between the fingers, graded for mixing and bedding, washed free of the clay, silt and organic matter that weaken a mix and hold water. The other, Mason Sand, is finer and is sold for mortar and for the thin bed under a paver.

Reaching for the wrong one is not fatal, but it shows. Coarse sand under a paver gives a bed that is harder to screed to a true level. Fine sand in a concrete mix changes the proportions the mix was designed around.

Choose washed sand where the material has to flow into a space and stay put

Three properties do all the work here: the grains are clean, they are coarse, and they are consistently graded.

• It flows. Poured into a trench or a form, it finds the shape without voids under a pipe or behind an awkward corner.
• It drains. Water moves through coarse clean sand rather than sitting in it, which matters wherever a backfill sits against a structure.
• It mixes predictably. With no clay or organic matter riding along, a batch behaves the same way as the last one.
• It compacts, to a point. Damp and tamped in shallow layers it firms up well. It never becomes structural.

That list points at four jobs: concrete and mortar mixing, bedding pipe and cable, backfilling trenches and post holes, and leveling or grading a surface before something else goes on it.

Skip it where the layer has to carry a load on its own

Sand is not a base. Under load it moves sideways to wherever it is not confined, which is why a sand layer that is not boxed in by something rigid slowly disappears at the edges.

Two requests come up regularly and both are misjudged.

A turnaround or parking pad. The idea of a sand pad is appealing because sand grades flat easily. In practice it ruts on the first wet day and the sand ends up in the lawn. A hypothetical 18 by 22 foot turnaround is 396 square feet, and at 4 inches that is 396 x 4 / 12 = 132 cubic feet, 132 / 27 = 4.89 cubic yards. Every yard of it would be gone within a season. That surface needs Crusher Run or Road Base compacted, with Driveway Gravel over it.

A French drain along a foundation. Sand in a drain trench is the opposite of what is wanted: it packs, it holds water, and it carries silt into the voids you were relying on. That trench takes Drain Rock or a clean graded stone, wrapped in filter fabric. The one place sand belongs in a trench is around a utility line, which is a different trench doing a different job.

Bedding a utility line in the same yard as that drain

Pipe and cable bedding is where this material is genuinely the right answer and no substitute is as good. Sand flows around the pipe barrel without leaving hollow spots, it does not contain stones that press into a coating, and it spreads a point load along the length of the run rather than concentrating it where a rock happens to sit.

A workable arrangement: a level trench bottom, a few inches of sand bedded and raked flat, the line laid on it, then sand brought up over the top before native soil goes back in. For a hypothetical run 40 feet long in a trench 18 inches wide, with 6 inches of sand in total: 40 x 1.5 = 60 square feet, 60 x 6 / 12 = 30 cubic feet, 30 / 27 = 1.11 cubic yards. Sand is figured at about 2,700 lb per cubic yard on this site, so 1.11 x 1.35 is about 1.5 tons.

A dog run, a sandbox, and what stays clean

The third request that arrives regularly is a side-yard dog run, and the honest answer is a qualified no.

Sand drains well and grades flat, so it starts out looking like the perfect surface. What it does not do is stay clean: it holds what lands on it, it cannot be hosed through the way an open stone layer can, and it tracks indoors on feet and paws. A hypothetical 6 by 30 foot run at 4 inches is 180 square feet, 180 x 4 / 12 = 60 cubic feet, 60 / 27 = 2.22 cubic yards, roughly 3 tons, and it will need replacing long before a stone layer would. River Rock over a free-draining base is the more practical surface there.

A play sandbox is a different matter. Coarse washed sand is clean of clay and organic material, though it is gritty by design rather than soft, so many people prefer the finer sand for that and keep this grade for the construction work.

Cubic yards for a 14 by 20 foot leveling course

Leveling is where the small quantities live, and it is worth working them carefully because sand depth is measured in single inches.

A hypothetical 14 by 20 foot area with a 1 inch leveling course: 14 x 20 = 280 square feet. 280 x 1 / 12 = 23.3 cubic feet. 23.3 / 27 = 0.86 cubic yards. At about 1.35 tons per cubic yard that is roughly 1.2 tons.

Add the bedding run above and the whole job is under 3 tons, which is one delivery. For anything less tidy than a rectangle, the sand calculator handles circles and up to five separate areas, with depth anywhere from a quarter of an inch to 24 inches.

Rain on delivery day, and what a wet pile weighs

Sand is the one material on this site where weather before the truck arrives changes the job.

A wet pile weighs more per yard than a dry one, sticks to the shovel, and cannot be screeded to a level until it dries out. If rain is forecast, plan to cover the pile as soon as it lands, and choose a dump spot that does not sit in the path of runoff from a roof or a slope. A tarp underneath is worth more here than with any stone, because the last few inches of a sand pile pick up whatever they are sitting on, and gravel or soil in a leveling course is exactly what you paid to avoid.

Set the quantity and the delivery date on this product page. Delivery is arranged at checkout by ZIP code, and the truck needs a clear route to a dump spot on firm ground. If the choice between the two sands is still open, send the application through the contact page and ask for a quote by email with the grade named.