#10 Stone Screenings in Michigan: 1/4 Inch Minus for Beds, Joints and Compacted Surfaces

The job stone screenings are bought to fix, over and over on lots across this state, is a paver patio that has dropped a corner. The pavers went down on a loose sand bed, three winters of frost lifted and dropped them, water pumped the sand sideways out of the low edge, and now the whole thing rocks underfoot. Screenings are the fine crushed material that answers that problem: a quarter inch minus blend of angular particles and stone dust that binds under compaction instead of staying loose.

Stone screenings beside mason sand, 3/8 inch stone and 22A road gravel

Four materials on this site look adjacent to one another and behave nothing alike.

Mason Sand is washed, ultra fine and never binds. That is a virtue in a mortar mix or a sandbox and a liability under paving, because it stays mobile for as long as water can reach it.

3/8" Crushed Stone is washed and open. It drains hard and holds voids, which makes it useful over a drain line, but it will not level to a flat bed and it will not hold a screed line.

22A road gravel also contains fines, and it also packs hard, but its top size is far bigger. It is a structural layer that carries weight, not a finishing layer you bed brick into.

Screenings are the finishing material. The particles are small enough to screed flat and to sweep into a joint, and the dust content is what turns a two inch layer into something close to a solid slab once it is wetted and tamped. Keep them in that role. They are not the structural base and should never be asked to be.

The side-yard dog run and the turnaround apron: two jobs it finishes well

A side-yard dog run is a good fit, and the reason is the fines. Rounded loose gravel scatters under claws and travels into the lawn; screenings compact to a firm, even surface that sheds rain instead of holding it, and a dog crossing it forty times a day does not churn it up. Over a prepared and compacted base with fabric between, a run like that stays tidy for years.

A turnaround or parking apron is the other one, with a caveat. Screenings make an excellent top dressing over a compacted 21AA limestone base, filling the surface texture and giving a smooth, hard finish that sheds water. What they cannot do is be the pad. Put four inches of screenings on bare southeastern clay and by the second spring you have a rutted gray paste.

The other regular uses are the small ones the material was made for: bedding flagstone and pavers, sweeping into the joints between units once they are set, and bringing a shallow subgrade to level before a shed, a deck footing or a concrete pour.

Why the French drain along the foundation is the one to keep it out of

This is the most damaging mix-up on the list. A French drain works because the stone around the pipe holds open voids that water moves through faster than it moves through soil. Screenings are the opposite of that: the dust is what closes the gaps. Fill a foundation trench with them and you have built a sponge that holds water against the wall you were trying to protect, which matters on the flat lake plain in the southeast and around Saginaw Bay where meltwater already stands for weeks.

Use Drain Rock or #67 Stone in the trench. Screenings can still appear on that job, as the leveling layer under a paved surface that sits above the drain, but never inside it.

Wetting it down and running the plate before anything goes on top

Sequence decides the result. The base under the screenings goes in first and gets compacted properly. Fabric goes over that on clay, to keep the fines and the soil from marrying. The screenings are then spread, wetted lightly rather than soaked, and compacted with a plate. Wetting matters because dry dust will not bind; damp dust locks.

Season decides the rest. Compaction needs unfrozen ground, so the window runs from the spring thaw into late fall, and it closes earlier in the Upper Peninsula and the northern Lower Peninsula than it does in the south. With frost reaching 42 inches under the Michigan Residential Code, anything that has to stay dead level through a winter, a hot tub base or a set of steps, is a conversation with a builder rather than a question a product page can answer.

Tons for a 12 by 26 dog run and a 22 by 26 turnaround top dressing

Both figures below are hypothetical. Start with the dog run down the side of the house, twelve feet wide and twenty-six feet long, finished with two inches of screenings over a compacted base.

• 12 x 26 = 312 square feet
• 2 inches is 0.167 feet, so 312 x 0.167 = 52.1 cubic feet
• 52.1 / 27 = 1.9 cubic yards

The published weight for screenings and dust on this site is about 2,900 lb per cubic yard, which works out at 1.45 tons per yard. So 1.9 x 1.45 = 2.8 tons.

Now a top dressing across a turnaround, twenty-two by twenty-six feet, at an inch and a half over an existing compacted base.

• 22 x 26 = 572 square feet
• 1.5 inches is 0.125 feet, so 572 x 0.125 = 71.5 cubic feet
• 71.5 / 27 = 2.6 cubic yards, and 2.6 x 1.45 = 3.8 tons

Round both up rather than down. A screed course always takes a little more than the arithmetic says, because it is filling the hollows in whatever is underneath. The stone calculator will do the same sum for circles and for up to five areas at once, and it carries a five percent addition, on by default, for exactly that.

If the area is an awkward shape, or you would rather have the figure checked before you commit to a tonnage, send the dimensions through the contact page and work from the answer.