Mason Sand in Maryland: The Fine Washed Sand for Finish Work

Run a handful through your fingers and the difference shows up immediately. The grains are small and even, with no grit that catches, no clay lumps and none of the silt streaks that turn a pile gray when it rains. That uniform texture is what the washing produces, and it is the reason this sand ends up in mortar tubs, under paver bedding and in sandboxes rather than holding up a driveway.

The gritty, uneven finish this sand is ordered to fix

The complaints that lead people here are all about the last half inch of a job.

• Pavers that rock underfoot because the bedding layer had lumps and coarse pieces in it that would not screed flat.
• Joints between flags that never filled properly, so weeds took them over within a season.
• Mortar that went off lumpy and would not tool to a clean line, usually because the sand carried clay.
• A sandbox or play area filled with something sharp enough that children stopped using it.

The fix in each case is a sand fine enough and clean enough to be the finish rather than the structure. Mason Sand is washed to take clay, silt and organic material out, and graded to a consistent fine grain.

What the bedding course sits on: Coastal Plain ground and Piedmont clay

• On Eastern Shore and Western Shore Coastal Plain ground, the native soil is already sandy in places, which tempts people to skip the base. Resist it. Native sand is not graded, it is not washed, and it does not carry a load evenly.
• On Piedmont silt loam and clay, water sitting under a bedding course is the enemy. The sand itself drains, but if the layer under it holds water through a freeze, the whole patio lifts and comes down out of level.
• Frost depth runs around 30 inches through most of the state, 24 inches in several Eastern Shore counties and 36 inches in Garrett County. No residential paver bed goes below that, so what protects the work is drainage under it rather than depth.
• On low ground near tidal water, where drainage is already slow after a nor'easter, the compacted base under the bedding sand needs to sit above the wet rather than in it.

Screeding the bed and sweeping the joints

The sequence is what keeps a patio flat, and the sand only enters it near the end.

• The compacted base goes in first, built and rolled to the finished profile. CR-6 or Crusher Run does that work.
• Set edge restraints before any sand goes down. Without a firm edge, a bedding course migrates outward and the perimeter pavers drop.
• Screed a thin, even bedding layer over the base using rails or pipe, then pull them and fill the grooves. Do not compact the bedding sand first, and do not use it to correct a base that is out of level.
• Lay the units, then compact the field with a plate over a protective mat, which beds the pavers into the sand from above.
• Sweep sand into the joints, compact again, and top the joints up. Wetting a dry, dusty load slightly before sweeping keeps the sand where you are putting it.

Frost, downpours and the joints that want topping up

• Expect to refill joints in the first spring. Rain washes fines out of an open joint and the freeze-thaw cycle works them loose, and a patio that has lost joint sand starts to shift.
• After a heavy summer thunderstorm, look at the low edge of the patio. Sand tracking out there means the edge restraint is not doing its job.
• On a play area, rake the surface over occasionally and keep it covered when it is not in use. Wet sand that stays wet grows things.
• Do not let a downspout discharge onto or under paver work. Move the water with River Rock or a proper drain run and the bedding course stays where it was screeded.

Working out sand for a play area, four bed frames and an apron

Square feet times depth in feet, divided by 27, gives cubic yards. Depth in inches divides by 12 first.

• Example, a playground surface 12 feet by 14 feet at 6 inches: 12 x 14 = 168 square feet. 6 inches is 0.5 feet, so 168 x 0.5 = 84 cubic feet, divided by 27 = 3.1 cubic yards.
• Example, leveling the frames of four raised vegetable beds, each 4 feet by 8 feet, with a 1 inch sand course under the timber footprint: 4 x 8 x 4 beds = 128 square feet. 1 inch is 0.083 feet, so 128 x 0.083 = 10.6 cubic feet, divided by 27 = 0.4 cubic yards. The sand levels the frames only; the beds themselves get filled with Garden Soil.
• Example, a paver apron for an RV or boat, 12 feet by 40 feet, bedding course at 1 inch: 480 square feet x 0.083 = 39.8 cubic feet, divided by 27 = 1.5 cubic yards. That is the bedding only. The compacted base beneath it is a much larger order and a different material.

At this site's published weight for mason and washed sand, about 1.35 tons per cubic yard and approximate, that is roughly 4.2 tons for the playground surface, about 0.5 tons for the four bed frames and about 2.0 tons for the apron bedding course.

Take the cubic yards through the sand calculator for tonnage, since the conversion uses the density figure the tool holds for this material.

The RV pad that wants stone underneath, not sand

An RV or a boat trailer concentrates a lot of weight on a small footprint, and sand does not carry it. What the pad needs is a properly built and compacted base, with Mason Sand appearing only as the thin setting course if the surface is going to be pavers. Where the pad is gravel rather than paved, the sand has no role at all. Ordering the sand and skipping the base is the single most expensive mistake on this page, because it is only visible after the first season of parking on it.

Measure the area, settle on your depths, and pick a tonnage and a date on this page. If the job is a mix of bedding and joints and you are unsure how to split the order, send the dimensions through contact and Maryland Rock Supply will go through it with you.