Mason Sand for Paver Bedding, Joints and Sandboxes

Most people land here choosing between two sands, and the choice is simpler than it looks. If the sand is the finish, or if it is bedding something that has to sit flat, you want the fine washed one. If the sand is carrying load or going under a slab, you want the coarse one.

This is the fine washed one.

What a yard of mason sand looks like tipped on the lawn

Ultra-fine, with a consistent grain size, and washed to take out clay, silt and organic material.

Tipped out, it holds a steeper heap than a coarse sand and it screeds off a board cleanly. Rub it between your fingers and there is no grit in the edges of it, which is the whole reason it works in mortar and under a paver.

The washing matters more than people expect. Clay and silt in a sand are what make a bedding course hold water, and water held under pavers through a New Hampshire winter is what pushes them out of line by April.

Bedding and joints around a fire pit surround

The common job. A fire pit with pavers or flagstone set in a circle around it, on ground that has been based and compacted first.

Order of work: compacted base, then roughly an inch of sand screeded flat, then the units set on it and tapped down, then sand swept into the joints. Do not build depth with the sand. It is a leveling course, not a structural one.

Other places it earns its keep here: mortar and grout for a chimney or a foundation repair, joints between flagstones on a walk, a sandbox for the camp, and the surfacing on a volleyball court where it should feel soft underfoot.

Under a pole barn pad or a single-car drive, it is the wrong sand

Two jobs that come up often, and this is not the material for either.

A pole barn or equipment pad carries point loads from posts and from whatever gets parked on it. Fine washed sand does not compact into anything that carries load, and it will not stay put once water moves through it. That pad wants a compacted layer of crusher run, and washed sand only if you are leveling beneath a slab.

A single-car gravel driveway wants something that binds. Fine sand under tires migrates into ruts and out to the edges, and by the second spring it is in the lawn. Drives take crushed gravel with a surfacing course over it.

The short version: fine sand goes where the load is a person or a paver, not a truck.

One inch of bedding, and why it must not grow

Screed to about an inch. Some people run three quarters. Very few good installers run more than an inch and a half.

The reason is settlement. A thick sand bed compresses unevenly under foot traffic and under freeze and thaw, and every low spot in the base telegraphs through it eventually. A thin bed cannot hide a bad base, which is the point: fix the base, then bed thin.

Screed off rails or pipe set to grade, pull the board once, and do not walk on the screeded sand. Footprints become dips in the finished surface.

Sand for a 9-foot fire pit circle and a flagstone run

Two hypothetical jobs. Mason sand runs about 2,700 lb per cubic yard on this site's published figures, near enough to 1.35 tons per yard, so the tonnages below are approximate. Other shapes go through the sand calculator.

Ring around a fire pit: 9 ft across overall, 5 ft fire pit in the middle, 1 inch of bedding

• Outer circle: 3.14 x 4.5 x 4.5 = 63.6 sq ft
• Fire pit: 3.14 x 2.5 x 2.5 = 19.6 sq ft
• Ring area: 63.6 - 19.6 = 44 sq ft
• 44 x 1 / 12 = 3.67 cu ft
• 3.67 / 27 = 0.14 cu yd
• 0.14 x 1.35 = 0.19 tons

Flagstone run, 30 ft by 4 ft, 1 inch of bedding

• 30 x 4 = 120 sq ft
• 120 x 1 / 12 = 10 cu ft
• 10 / 27 = 0.37 cu yd
• 0.37 x 1.35 = 0.5 tons

Together, about half a cubic yard, plus a little for sweeping the joints. Bedding sand quantities are small, which is why people underestimate the base beneath them and overestimate this.

Stone dust, washed sand and what goes under the sand

Stone dust is the one to weigh against this for a patio. It sets harder and holds a paver more firmly. Mason sand stays loose and is kinder to work with, and it is the one to use where the sand itself is the surface.

Under all three, the base. That does not change.

Set quantity and delivery date on this page. Delivery is arranged at checkout by ZIP code, and the truck needs firm ground with room to back and dump.