Washed Gravel

Unwashed crushed stone comes off the crusher with a mix of coarse rock plus stone dust and fine particles. Washing removes that dust and silt, leaving only the clean stone. That single difference changes what the material is good for. With the fines gone, void space between the stones stays open, so water passes straight through instead of being slowed or blocked. That is why washed gravel is the go-to for drainage applications: French drains, septic fields, pipe backfill, and under-slab layers where trapped moisture is the enemy. The tradeoff is that those same fines are what let unwashed material lock together under a compactor. Remove them and the stone has nothing holding it in place except gravity and friction between particles. So washed gravel is a drainage material first, not a structural base material, and most installation mistakes come from treating it as the latter.

Most projects use 3/4" washed stone (#57), with 3/8" offered for tighter, more walkable surfaces and 1"-2" for larger drainage channels or faster percolation. For drainage trenches, line the excavation with landscape fabric before placing stone, which keeps surrounding soil from migrating in and clogging the voids over time. For decorative beds and paths, fabric under the stone stops it from sinking into soil and cuts down on weed growth. For sub-base use under slabs or pavers, place washed gravel in thin lifts and compact each lift, understanding it will never lock as tightly as a material with fines. Always add edging around beds and paths, since loose stone without a physical boundary will migrate onto lawns, driveways, and storm drains within a season or two.

Compared with crusher run (unwashed crushed stone). Crusher run keeps its stone dust and fines, which fill voids and let it compact into a firm, load-bearing surface, making it the right choice for driveway bases. Washed gravel has those fines removed, so it drains far better but will not compact or interlock, making it the wrong choice anywhere traffic load matters.

Compared with pea gravel. Pea gravel is naturally rounded and smaller, around 1/4" to 3/8", softer underfoot but prone to shifting. Washed gravel in angular form, like 3/4" #57, gives more stability for paths and drainage work, while pea gravel stays the more decorative, barefoot-friendly option.

How much washed gravel do I need. Find cubic yards with length in feet times width in feet times depth in feet, divided by 27. Convert to tons at roughly 1.4 tons per cubic yard if your supplier sells by weight. As a coverage guide, one cubic yard covers about 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. Add 5 to 10 percent extra to account for settling after rain and traffic.

How it is sold and delivered. Washed gravel is typically sold by the ton or by the cubic yard, and since a ton runs about 0.65 to 0.74 cubic yards, pricing works out similarly either way. Bulk delivery is standard for any quantity beyond a few bags, dropped on site as loose stone. Confirm whether you are getting rounded washed river gravel or angular washed crushed stone, since the two perform differently.