Gravel Delivery FAQ for Tennessee Hill Lots and Hobby Farms

Almost nobody arrives here wanting a definition. The decision in front of you is usually how many layers the job needs, how deep each one goes, and whether a loaded truck can get to the spot where you want the pile. The answers below run in that order: the things people get wrong first, then the practical end of placing an order.

Keeping stone where you put it on a grade

My drive runs downhill. How do I stop the gravel ending up at the bottom?

Three things hold material on a grade, and the surface is the last of them. First, shape: a crown or a consistent fall sends rain across the drive and off the edge instead of down the middle of it, and a channel down the center of a drive will move stone every storm. Second, cross drains or a ditch to take that water somewhere before it builds speed. Third, material choice. Angular crushed stone keys together and stays put far better than rounded stone, so pea gravel and river rock belong on flat beds and paths rather than on a slope. An edge restraint, a timber, a mowing strip or a shallow trench, keeps the sides from spreading.

Fines and depth: why two gray piles behave differently

Two gray piles, one drains and one locks up. What makes the difference?

Fines. Washed grades such as #57, #67 and drain rock have the stone dust screened out, so the gaps between the pieces stay open and water runs through them. Crusher run and Dense Grade Base keep the dust in the mix, so under a roller the fines migrate into the voids and the layer locks into something close to a slab. That is why one is for drainage and the other is for carrying weight, and why neither substitutes for the other. A drive built on washed stone alone stays loose. A French drain packed with crusher run stops draining.

What decides how deep the compacted base goes under ground a car and a tractor both use?

The heaviest thing that crosses it, and then the ground underneath. A drive that only sees a car is a different build from one a pickup with a loaded trailer uses, and different again where a tractor or a delivery truck turns regularly, and each step up wants a thicker compacted section. No depth table is published on this site, so take the guidance on the product page as the starting point and add depth for soft clay, wet ground and the heavier vehicle rather than hoping compaction makes up for it. Whatever figure you settle on is a finished depth, so more loose material goes down to reach it, and on soft clay a separation fabric keeps the stone and the clay from mixing. Fabric is not sold here, so that comes from a local landscape supplier.

Leftovers, local names, layered jobs and ground that stays soft

I have a few yards left over. Keep it or lose it?

Crushed stone keeps indefinitely and is worth having. A few spare yards of crusher run fills the potholes that appear at the bottom of a slope after a wet winter, and washed stone keeps for the next trench. Store it off the grass on a tarp or a hardstanding, because a pile left on a slope loses its fines to the first heavy rain and what is left behaves differently. Soil and mulch are the opposite. They compost down, pick up weed seed and go sour in a heap, so order those closer to the amount you will actually spread.

I was told to order dense grade aggregate. Which product is that?

The everyday base stone that most people here call crusher run, and it is sold as Crusher Run at three quarter inch minus. The confusion comes from the spec side. Road base is specified by TDOT as mineral aggregate base at Grading D, which is how material gets written into a road or site specification rather than something the storefront certifies. The graded one inch minus product on this site is listed as Dense Grade Base and is the heavier of the two. Pick by top size and by what will be driving on it, and if you are working to a written spec, compare it against the size and grading lines on the product page.

How do I plan a job that needs a base and a surface layer?

Treat them as two separate orders and two separate calculations, because they are different materials at different depths and often different tonnages. Work the base first, since it is the deeper of the two, then the wearing course over it. Have the base delivered, spread and rolled before the surface material arrives, so you are not moving one pile to get at the other. If both loads have to land on the same day, mark two drop spots and keep them well apart.

The ground is still soft from the rain. Should I wait?

Usually, yes. Saturated clay has no strength to lend, so anything rolled into it in a wet week will find its level later, and a truck on soft ground is its own problem. A run of dry days before and after the work is worth more than any extra depth. Where waiting is not an option, the usual approach is a separation fabric over the subgrade with a coarser stone as the first lift, so the load bridges the soft ground rather than sinking into it. Either way, shape and drain the subgrade before any stone goes down.

Building the drive up from the subgrade

Dense Grade Base and a wearing course: what has to happen to the ground before either lands?

Strip the sod and topsoil out of the footprint first, because anything organic rots and leaves a hollow. Shape the subgrade to the fall you want the finished surface to have, then compact it. On soft clay, lay a separation fabric. Build the base with crusher run, or Dense Grade Base for heavier traffic, in lifts of three to four inches, damping and rolling each lift before the next. Finish with a wearing course of driveway gravel or #57 stone. Size the two layers separately with the calculators, and check the drop spot before you book the load.

Everything about the order itself sits one page over. Checkout, what a loaded truck needs to reach a hill-lot drop spot, and the pile it leaves behind are all on the delivery page, which also answers what to do when the lane takes more than you bought: order the balance on its own rather than reopening a load with a date on it, under the refund and order-change policy published there. For a quantity you want checked before ordering, the contact page takes measurements and a ZIP.

Who operates Tennessee Rock Supply?