#73 Stone in Indiana

Most people land on this page holding one question: do I want the size that packs tight and smooth, or the coarser one that carries the load? On rolling moraine ground where an outwash pocket drains in minutes and the till ridge twenty feet away holds water for a week, that question gets answered by what the layer is being asked to do. #73 stone is the finer of the two dense graded sizes, three quarter inch minus with stone dust worked through it, and it is bought when the surface matters.

Order #73 stone when these three things are true

• The layer underneath is already firm, or you are building a pad where the load is spread rather than concentrated.
• You want a surface that closes up tight, sheds water sideways and takes a blade cleanly in spring.
• The finished level matters, because a smaller top size lets you hold a grade within an inch.

Skip it when the ground is telling you otherwise

• The subgrade is soft muck or peat out of a kettle low, which is common in the lake country. Stone placed on that keeps disappearing into it. Correct the grade first with fill dirt and a separation layer.
• Water needs to move through the layer rather than across it. The fines in #73 stone close those paths, which is exactly the trait drain rock does not have.
• The lane carries loaded grain trucks or a combine across wet till. That calls for the deeper structural layer of #53 stone with the finer size used as a topping over it, if at all.

INDOT lists both in Section 904 of its standard specifications, which is how contractors, county crews and quarry dispatchers in this state refer to them. Treat the number as the local vocabulary for a gradation, not as paperwork that travels with a load.

Jobs it handles on moraine and outwash ground

Resurfacing a drive that has gone rough. Once the old surface has been bladed flat and the ruts filled, a thin layer of #73 stone knits into what is already there and gives the drive a tight top that sheds rain toward the shoulder instead of holding it in wheel tracks.

Shoulders and lane edges. The edge of a gravel lane is where material migrates first. A smaller top size stays put better on a shallow slope than an inch-and-up stone, and it rakes back into line without a machine.

Pads for sheds, hot tubs and equipment. Spread and compacted in lifts, it forms a level working platform. Where a kettle pond sits downhill, keep the pad crowned so meltwater runs off it rather than sitting against the structure.

Under pavers and flagstone. It compacts to a stable level bed, with bedding sand over it doing the fine setting work rather than the structural work.

Base course or finished surface, and why the answer changes with the truck

As a base course it goes down in lifts of three to four inches, each compacted while the material still holds moisture, until the design thickness is reached. As a finished surface it goes on thin, two inches or so, over something already compacted.

Depth follows the heaviest thing that will use it, not the average. A car drive over firm, well-drained outwash gravel can work on a shallower total section than the same drive on wet clay till, and a lane that a loaded truck uses in March needs more section than either. Where the lane crosses a low spot, the section needs to be deeper there than on the ridge, because freeze and thaw work hardest where water sits. Local footing depths for any structure on the pad are set by the county or city building department, and those are deeper in the northern counties than in central Indiana.

Sizing a barn pad, a fire ring apron and a creek channel

Hypothetical layouts, worked through so you can copy the method. Length times width times depth in feet, divided by 27, gives cubic yards.

Equipment pad, 30 feet by 40 feet at 6 inches. 30 x 40 = 1,200 square feet. Six inches is 0.5 feet. 1,200 x 0.5 = 600 cubic feet. 600 divided by 27 = 22.2 cubic yards.

Apron around a fire ring, a 14 foot circle with a 5 foot ring left open in the middle, at 3 inches. Circle area is 0.7854 times the diameter squared: 0.7854 x 196 = 153.9 square feet, less 0.7854 x 25 = 19.6, giving 134.3 square feet. Three inches is 0.25 feet. 134.3 x 0.25 = 33.6 cubic feet, or 1.2 cubic yards.

Compacted bed under a dry creek channel, 45 feet by 3 feet at 4 inches. 45 x 3 = 135 square feet. 135 x 0.333 = 45 cubic feet, which is 1.7 cubic yards.

This site publishes crusher run and road base at about 3,000 lb per cubic yard, roughly 1.50 tons per yard, which puts those three at approximately 33.3 tons, 1.8 tons and 2.6 tons.

Loads are sold by weight, so take your own dimensions to the crusher run calculator for the tonnage. It takes a rectangle, a circle or up to five separate areas, depth in inches, and adds a 10 percent margin by default, which you can untick.

Before the truck turns in off the county road

Pick a date, then a quantity, on this page. Delivery is arranged at checkout from the ZIP code you enter.

Have one clear dump spot chosen and marked, on ground firm enough to hold a loaded truck with its bed up. Move vehicles, boats and anything with a trailer tongue out of the swing. If the lane is narrow, know where the truck will turn around before it arrives rather than after. Someone should be on site who can point at the spot. If you are unsure whether the approach works, describe it through the contact page and settle it in advance.