#89 Crushed Stone in Virginia: the Small Size That Packs

The weather window matters more for this material than for almost anything else sold here. #89 crushed stone only does its job once it has been compacted and wetted in, and a joint filled during a long soggy spell on Piedmont clay never sets up the way the same joint does in a dry stretch of spring or early autumn. Fill it in midsummer and it packs, then the first thunderstorm that stands over the house washes the fines out of the top of the joint before anything has knitted.

What the fines in it change, against the sizes it sits between

The size runs about 3/8 inch down to fines, angular crushed rock. That trailing phrase is the entire product. Everything below is a consequence of it.

The pairing that catches people out is the first one. #8 and #89 sound like neighbors and behave like opposites. One is bought so water can pass, the other is bought so the layer will hold still. Order by what the layer has to do, not by which number looks closer.

Booking the work for a dry stretch, not a wet one

• Spring and early autumn suit this material best across the Piedmont and Northern Virginia: the ground is workable, the fines take a wetting-in without turning to slurry, and there is time for the joint to firm before the next hard season.
• Late summer into autumn is storm season on the coast and through Hampton Roads. A fresh joint or a new bedding course is vulnerable until it has been compacted and settled, so watch the forecast rather than the calendar.
• Midwinter in the Blue Ridge and the western valleys puts frozen ground under the work, and compaction into frozen material is wasted effort.
• After any long wet spell, give the subgrade time to drain before you start. Saturated clay under a bedding course moves later, whatever you put on top of it.

Clear the joint or the bed of the previous material first, get the surface to the profile you want, then bring the stone in and work in a run you can finish and compact the same day.

Three jobs put to #89 crushed stone, and the one it should not be given

A garden path. This is the natural fit. Used as the bedding course under flagstone or brick, or swept into the joints between them, the small angular pieces and their fines knit together and hold the pieces from shifting underfoot. On a path that carries a wheelbarrow as well as boots, build the bedding course over a compacted base rather than straight onto clay.

A long rural lane. This is the one to refuse. A lane surfaced with a small stone of any kind ruts under tires, and a material this fine washes down the crown and into the ditch with the first real storm. A lane wants a dense-graded base laid and rolled, which in Virginia means 21A, then a wearing course on top of it. Keep this stone for the hardscape details around the house at the end of the lane.

Ground being prepared for new lawn. Not a stone job at all. Seed needs a soil bed with something in it for roots, so that work belongs with screened Top Soil. The small stone reappears only where the lawn meets hardscape, in the joints of a mowing strip or a path edge.

Depth in a joint, a bedding course and a chip seal

• Paver and flagstone joints: fill to the full depth of the joint, brush in, compact, then top up and repeat. Joints always take a second pass once the first has settled in.
• Bedding course under flagstone or pavers: an inch to an inch and a half, screeded flat, over a compacted base. Deeper is not better here, since a thick bedding layer moves.
• Path surfacing over a prepared base: around 2 inches, compacted.
• Chip seal: laid to the rate the contractor working the job specifies, since it is applied to hot binder rather than spread by depth.

Yards and tons for a 38 foot path, a lane it will not surface, and a seeded strip

Square feet times depth in inches divided by 12 gives cubic feet. Divide by 27 for cubic yards. This site's calculator pages put small crushed chips near 2,800 lb per cubic yard, about 1.40 tons, and the figures below use that.

• Example, a garden path 38 ft by 3 ft with a 1.5 inch bedding course: 114 sq ft x 0.125 = 14.3 cu ft. 14.3 / 27 = 0.5 cubic yards, roughly 0.7 ton.
• Example, the rural lane, 400 ft by 10 ft, built correctly as 4 inches of base: 4,000 sq ft x 0.333 = 1,333 cu ft. 1,333 / 27 = 49.4 cubic yards. Dense-graded base is nearer 3,000 lb per cubic yard on this site's figures, about 1.50 tons, so that is roughly 74 tons of 21A, and none of it is this product.
• Example, a 30 ft by 40 ft strip being brought up for seed with 2 inches of screened topsoil: 1,200 sq ft x 0.167 = 200 cu ft. 200 / 27 = 7.4 cubic yards. Screened topsoil runs about 2,200 lb per cubic yard, roughly 1.10 tons, so about 8.1 tons.

Joints are the exception to all of this, because the volume depends on joint width and paver depth rather than on an area. Work them out by the run and add a margin for the second filling. The stone calculator will check the area figures.

Order a quantity and a delivery date here once the base is compacted and you have a settled forecast. Delivery is arranged at checkout from your ZIP code, and the truck needs a clear route in and a spot it can tip on.