#89 Crushed Stone for Paver Joints and Flagstone Beds in Indiana

A flagstone walk laid on red clay over limestone moves for a reason. The clay under it holds water through a mild but repetitive south-central winter, the freeze lifts each stone a fraction, and whatever was packed between them washes or drifts out by the second spring. #89 crushed stone is the small angular size bought to stop that. It runs about 3/8 inch down to fines, and the fines are the point: they wedge between the angular pieces and lock the fill so it stays where it was swept.

What does a small angular stone do on red clay over limestone?

It gives the paving something to sit in that will not stay loose. Compacted, the mix of chips and fines closes up into a firm, close-fitting layer, which is what a walk or patio needs under and between its stones.

What it does not do is drain. That is the trade every buyer on this ground has to make consciously. Around the karst plain, water leaving a paved area has to be aimed at something, and aiming runoff into a sinkhole is how fill gets washed underground and how a collapse starts. Handle the water below and away from the paving with a proper drainage material, then use this stone where the finished work needs to lock. Separate the two jobs and both work. Combine them and neither does.

Does #89 crushed stone go under the flagstone or between it?

Both, in different thicknesses.

Under the stone, it is the setting bed: a thin screeded layer over a compacted base, raked flat, with each flag bedded into it and tapped down so it sits without rocking. The bed is not the base. The base is a compacted dense graded layer of #53 stone, and skipping it is the most common reason a walk on clay goes wavy.

Between the stones, it is joint fill: swept in dry, worked down with a stiff brush, then settled with water or a light plate pass. Fill in two or three goes rather than one, because the first sweep always drops once it is wetted. The same material is used in chip seal surfacing and turns up in concrete mixes, which is why the load in the yard looks familiar to anyone who has watched a county road crew.

A garden path, a new lawn and a hot tub pad: which of the three suits it?

The garden path is the straightforward fit. Over a shallow compacted base, this stone screeds into a firm walking surface with a tight, even texture, and it holds an edge better than anything rounded does. Contain it with timber, steel or a set edge and it stays a path rather than spreading into the beds either side.

The hot tub pad is a partial fit. A filled tub is a serious load, and the layer carrying it is a compacted base, not a small stone. Build the base first, then use this size as the thin bedding course that levels the pavers or slabs the tub sits on. Get the base wrong and no bedding material will save it.

The new lawn is not a fit at all, and it is worth saying plainly. Seed and sod need organic material and moisture-holding structure, which crushed stone has none of. That job wants screened topsoil spread over the graded ground, with garden soil where beds are going in. The only place this stone belongs in a lawn project is under a mow strip or path crossing it.

How much do those three take, in yards and tons?

Worked examples, hypothetical, with the arithmetic shown. Length times width times depth in feet, divided by 27. The site's own published figure for small chips of this family is about 2,800 lb per cubic yard, near enough 1.40 tons per yard.

The garden path, 3 feet wide and 45 feet long at 3 inches. 3 x 45 = 135 square feet. Three inches is 0.25 feet, so 135 x 0.25 = 33.75 cubic feet. Divided by 27 that is 1.25 cubic yards, about 1.8 tons.

The hot tub pad, 8 feet square, with a 1 inch bedding course. 8 x 8 = 64 square feet. One inch is 0.083 feet, so 64 x 0.083 = 5.3 cubic feet, or 0.2 cubic yards, roughly a quarter of a ton. The compacted base under it at 6 inches is a separate order: 64 x 0.5 = 32 cubic feet, which is 1.2 cubic yards of dense graded stone.

The lawn, 2,000 square feet needing 3 inches of soil. 2,000 x 0.25 = 500 cubic feet, or 18.5 cubic yards, and none of it is this product.

What can go wrong on karst ground before the stone is even ordered?

Look at where the water currently goes, not where you would like it to go. On the limestone plain, surface water disappears into swallow holes and sinking streams rather than running to a ditch, and a new paved area changes how much arrives and how fast. A sinkhole taking clean runoff is one thing. A sinkhole taking runoff that is carrying soil and fine material is how voids open under the ground you just built on.

The second thing to check is the season. Winter and early spring turn the clay slick and soft, and any base compacted into wet clay will move once it dries. Late spring through fall is the honest working window, and finishing before the ground freezes gives the work a winter to settle in rather than a winter to come apart.

How is it ordered, and where should the pile land?

Take your own measurements to the stone calculator, which handles rectangles, a circle or up to five separate areas, works in feet for length and width and inches for depth, and adds 5 percent by default, which gives spare for topping up joints later. Indiana Rock Supply lists this material as #89 Crushed Stone, so pick a delivery date on this page and then the tonnage.

Delivery is arranged from the ZIP code you put in at checkout, and the driver needs a firm spot with clear space above to raise the bed. On a sloping southern lot, pick a dump point uphill of the work if you can, so wheelbarrowing is downhill rather than up. Comparing the small sizes before you commit is easier from the full product list.