#57 Stone in Maryland: Washed Drainage Stone at 3/16 to 1 Inch

More #57 stone leaves this catalogue for yard drainage than for anything else, and the reason is written into the ground. A Silver Spring or Ellicott City lot sits on silt loam and clay weathered from crystalline rock, which sheds a thunderstorm across the surface and then holds what soaks in. Move that water and the problem goes away; try to soak it away into clay and it comes back every August. Washed stone with nothing fine in it is what makes a drain run rather than clog.

Reading a #57 ticket line by line

Maryland sells washed stone by number, and #57 is the workhorse of that series. The nearest neighbors are #67 Stone a little smaller and #8 Crushed Stone smaller again, and the choice between them is mostly about how tight a space the stone has to fill.

Five jobs on a suburban Maryland lot, and the depth each one wants

Two things #57 does not do. It will not compact into a hard, bound surface, so it is the wrong choice where a layer has to lock up under vehicle weight; that is CR-6 territory. And it is far too coarse to set pavers directly on, which is a job for a fine setting bed.

Clay, a high water table and 30 inches of frost

• Across the Piedmont, storm runoff arrives fast off rolling ground and the silty subsoil goes soft when saturated. A drain here is moving surface and shallow water away, not draining an aquifer.
• On the Eastern Shore and the low Western Shore, flat ground and a high water table slow everything down. A trench dug too deep fills from below and the drain never gets a chance to fall anywhere.
• In the limestone valleys near Hagerstown and Frederick, water goes down through cracks in the rock, and concentrating runoff at one point is what opens sinkholes. Spread the discharge rather than pointing it at a single spot.
• Frost depth is around 30 inches in most county codes, 24 in several Eastern Shore counties and 36 in Garrett County. Water held in a saturated trench through a freeze is what heaves the work above it, which is the argument for a stone with open voids rather than one that holds moisture.
• Within 1,000 feet of tidal water, Critical Area rules count gravel and stone surfaces toward lot coverage. A large decorative bed is worth checking before it goes in.

Counting stone for a 14 by 16 patio bed and two smaller jobs

Square feet times depth in feet gives cubic feet; divide by 27 for cubic yards. Depth in inches divides by 12 first.

• Example, a paver patio base 14 feet by 16 feet at 6 inches: 14 x 16 = 224 square feet. 6 inches is 0.5 feet, so 224 x 0.5 = 112 cubic feet. 112 divided by 27 = 4.1 cubic yards.
• Example, a dry creek bed 30 feet long averaging 3 feet wide at 4 inches: 30 x 3 = 90 square feet. 4 inches is 0.333 feet, so 90 x 0.333 = 30 cubic feet, divided by 27 = 1.1 cubic yards.
• Example, a fire pit surround, a 3 foot ring of stone around a 4 foot pit, giving a 10 foot outer circle: 10 x 10 x 0.7854 = 78.5 square feet, less the pit at 4 x 4 x 0.7854 = 12.6 square feet, leaves 66 square feet. At 3 inches that is 66 x 0.25 = 16.5 cubic feet, divided by 27 = 0.6 cubic yards.

At this site's published weight for #57 stone, about 1.40 tons per cubic yard and approximate, that is roughly 5.7 tons for the patio base, about 1.5 tons for the dry creek bed and about 0.8 tons for the fire pit surround.

Put those cubic yards into the stone calculator to check the tonnage before you order.

Getting the load onto the lawn without wearing a path across it

Delivery is arranged at checkout from your ZIP code, and the truck needs clear access to somewhere it can tip and reverse out of. Choose the drop spot with the wheelbarrow route in mind, because washed stone is heavy work and every extra 30 feet is a trip you make forty times. A tarp under the pile keeps the last of the stone out of the grass and makes the scraping up quicker.

Measure the job, take the cubic yards through the calculator, then set a tonnage and a delivery date on this page. If the run has changes of width or an awkward corner, send the measurements through contact before you commit to a figure.