3/4" Crushed Stone for Tennessee Pad Bases and Drainage Trenches

The order that comes in most often for this size is a base course under something else. A hot tub pad, a shed floor, a patio cut into a slope, a footing on ground where limestone turns up two feet down. 3/4" crushed stone is angular and clean, so it locks up tight under a plate and still lets water leave through the layer, and on cherty clay that second half is what stops a pad going soft from below.

Why most base orders here wait for the clay to dry

Winter and spring are the wet seasons across the state, and saturated clay is the reason base work slips rather than frozen ground. A plate on a soaked subgrade kneads it, the fabric ends up bedded into mush and the layer you build on top of it never sits still.

Late summer through October is the reliable run on the Highland Rim and in the valleys. A dry spell in December works too. What matters is the subgrade, not the air temperature, so dig a test hole and look at it before you book anything.

Cutting to full depth, then fabric, then stone

Excavate the whole section in one go, base course included, and check the fall while the hole is open. Everything built on a hill lot wants a slope away from the structure and a place for water to arrive at.

Woven permeable geotextile goes straight onto the subgrade. Skip it and cherty clay works up into the voids over a few wet winters until the base holds water instead of shedding it. Then bring the stone in and compact it in lifts of three to four inches rather than dumping the full depth and hoping.

What 3/4" crushed stone is ordered for on hill lots

Four jobs cover most of it.

Base courses under pads, patios, sheds and small slabs, where the layer has to carry weight and drain at the same time. Drainage trenches and French drain runs, where the open gaps are the whole point. Backfill behind a retaining wall, keeping water off the back of the structure. And concrete mixes, where an angular clean coarse aggregate is what the mix design calls for.

Where it does not belong is on top. A clean stone has no fines to bind it, so a surface built from it stays loose, throws pieces and is hard work to walk on. A lane or a turnaround wants Crusher Run or the graded Dense Grade Base instead.

The other place it earns a look is under a shed or a small slab on ground that stays damp. A six inch course over fabric gives the slab something firm to sit on and gives the water under it somewhere to travel sideways to, which on a cut-in hillside site matters more than the depth does. Take that layer out past the edge of the slab rather than stopping it at the formwork, so water leaving the base has somewhere to arrive rather than a wall of clay.

A hot tub pad base, and the trench that goes in before seed

Two hypothetical examples, worked as the site's calculator works: length by width by depth in inches, divided by 12, divided by 27. Stone in this family runs about 2,800 lb per cubic yard on this site's published figures, near enough 1.4 tons to the yard. The washed #57 stone listing sits in the same size family and carries the same weight here.

A hot tub pad 10 feet by 8 feet is 80 square feet. A six inch base gives 80 x 6 = 480, divided by 12 = 40 cubic feet, divided by 27 = 1.48 cubic yards, about 2.1 tons.

Prepping a graded lot for a new lawn brings in the second one, and the stone is not the lawn. Seeding goes to Top Soil; what this material does on that lot is the trench that takes water off it. A 60 foot run, 18 inches wide and 18 inches deep, is 60 x 1.5 x 1.5 = 135 cubic feet, divided by 27 = 5 cubic yards, about 7 tons. Put your own figures through the stone calculator.

The dog run is the one to turn down

A side yard run for a dog comes up regularly with this size and it is the wrong pick. Three quarter inch angular pieces are hard underfoot, awkward on paws, and coarse enough that waste drops between them and stays there.

A run wants a finer surface over a compacted layer. 3/8" Natural Pea Gravel reads softer, and walkway gravel gives a firmer walking face. Keep this stone for the base under either one if the ground is soft.

The first wet winter, and what the base needs afterwards

A properly compacted base under a pad should need nothing. Consolidation happens in the first few weeks and then it stops, which is why the base goes in well before the pavers or the slab rather than the same afternoon.

Exposed work is different. Stone in an open trench settles as silt and leaf litter find the voids, so plan to rake the top back and add a little the year after. Where a trench has clay above it, expect the top inch to look dirty within a season. That is cosmetic. The layer is done when water still leaves at the outlet. Measure, work the tonnage, then set a quantity and a date here with Tennessee Rock Supply, or check access through contact if the drop has to happen uphill of the work.