#89 Crushed Stone for Tennessee Paver Joints, Pads and Walk Beds

Two listings on this site top out at about three eighths of an inch, and they do opposite jobs. The clean one has the dust screened out so water runs through it. #89 crushed stone keeps some of the fines, which is why it settles into a tight, firm layer when it is compacted, and why it belongs in joints, bedding courses and chip seal instead of in a drain. Order the wrong one and either your pavers rock underfoot or your trench holds water.

The dry two weeks a paver job waits for

Fines only bind when they are damp, not soaked, and cherty clay under the pad has to be firm before anything goes on top of it. That rules out most of February and March on the Highland Rim, when the ground has been wet for weeks and a plate compactor just kneads the subgrade.

Late summer into October is the easy run here, and a dry week in early winter works too. Watch the ten-day outlook rather than the calendar, because one Tennessee thunderstorm on an open screed will wash the fines out of it and leave you re-screeding.

Getting the pad cut and drained before the stone lands

Excavate to full depth first, including the base course, and check the fall while the hole is open. A pad wants a slight slope away from anything built, and on a hill lot it wants somewhere for that water to go once it gets to the low edge.

Lay woven geotextile over the subgrade, put the base stone in and compact it in lifts, and only then bring in this material. The bedding course is the last thing before the pavers, so it goes down on the day it is used. A screeded bed left open over a wet night is wasted work.

What the fines in #89 crushed stone do in a joint, a chip seal and a walk bed

In a joint, the small angular pieces and the fines wedge together and stop pavers shifting against each other. In a chip seal, the same angular shape is what keys into the binder. In a bedding course, the layer screeds flat and then holds that flatness under load, which is the whole point of a setting bed.

Chip seal is the other place it shows up, and it is worth knowing why the same material suits a road treatment and a garden path. Both want small angular pieces that key into whatever is holding them, binder in one case and their own fines in the other.

It is also accepted in concrete mixes that call for a compactable crushed aggregate. What it is not is a drainage material. Water soaks through slowly and then stops, so keep it out of trench bottoms and out of anything built to move volume. For that work the clean grades exist, starting with #8 crushed stone in tight details and #67 stone where a pipe is involved.

Against the finer option on this site, Screenings at a quarter inch minus screed flatter and are the usual setting course under flagstone. This grade has more stone in it and less dust, so it holds shape better in a joint and under a walk that takes a wheelbarrow.

A hot tub pad on cherty clay, and the dog run that wants a different top

Two hypothetical examples. The method is length by width by depth in inches, divided by 12, divided by 27. Chips in this family weigh about 2,800 lb per cubic yard on this site's published figures, near enough 1.4 tons to the yard.

A hot tub pad 9 feet square is 81 square feet. A bedding course at 1.5 inches works out at 81 x 1.5 = 121.5, divided by 12 = 10.1 cubic feet, divided by 27 = 0.37 cubic yards, roughly half a ton. The six inch base course beneath it is a separate and much larger order of washed #57 stone.

A side yard dog run 30 feet by 6 feet is 180 square feet. Three inches of this material compacted in gives 180 x 3 = 540, divided by 12 = 45 cubic feet, divided by 27 = 1.67 cubic yards, about 2.3 tons. That layer is what stops the run turning to mud, but it is not the surface. Finish it with 3/8" Natural Pea Gravel or walkway gravel, because compacted fines get tracked indoors on wet paws. Check your own figures on the crushed stone calculator.

Seedbed for a new lawn is not a job for crushed stone

The third request that comes in with this material is ground prep before seeding, and it is worth saying plainly that no crushed stone belongs under grass. Roots need depth and organic matter, and a compacted stone layer gives them neither.

Raising and leveling before seed is a soil job. Use Fill Dirt to build the contour, then a working depth of Top Soil over it for the seedbed itself.

Topping up joints after the first Tennessee winter

Joints lose a little material in the first year, partly to rain and partly to the broom that swept them in. Plan a top-up the spring after the job, sweeping fresh material in dry and then wetting it down so it settles.

Once the pad has been through a wet winter and a hot summer, it usually stops moving. Keep a wheelbarrow load back from the original order for that, and for the odd paver that needs lifting and re-bedding. Measure, run the numbers, then choose a quantity and a delivery date here, or raise an access question through contact first.