Mason Sand for Massachusetts Paver, Mortar and Play Work

Stony glacial till over shallow ledge decides how deep a patio can be dug in most of this state, and mason sand is the layer that turns up after that argument is settled. It is the thin, fine, washed material that goes between a compacted base and the pavers, and then between the pavers themselves. It is not what holds the patio up. Getting that order right is most of what separates a surface that is still flat after five winters from one that is not.

Why mason sand work starts after the ground thaws, not before

Compaction stops working on frozen ground, so the base underneath cannot be built through the winter months, and the sand cannot go down until the base is finished. That puts almost all of this work between the spring thaw and late autumn.

The edges of that window differ by where you are. On the deep outwash sand of Cape Cod and the Islands, the ground drains fast and the frost-free season is longer, so work can start earlier and run later. On the dense lower till under Greater Boston and the Worcester plateau, spring ground stays wet for weeks after the snow has gone and the base work waits. In the Berkshires and the western hilltowns the season opens latest and closes earliest of anywhere in the state.

Late autumn is the other trap. A patio bedded and jointed just before the first freeze has not had a season of rain to settle the joints, so plan to top up joint sand in spring as a matter of course.

Getting the base right on till before any sand goes down

The most expensive mistake with this material is asking it to do a base's job. Sand does not compact into a load-bearing layer. Bedded thick to make up for an uneven base, it rolls under load and the pavers dip.

Build the sequence properly. Excavate to firm subgrade. Place and compact Crusher Run or Processed Gravel in lifts until the base is level and solid. Screed a thin, even bedding layer over that. Lay, compact, then sweep sand into the joints.

On soft or wet till, geotextile between subgrade and base earns its keep, because without it the two mix and the base thins out where it is most needed.

Paver beds, joints, mortar and a sandbox that drains

The material is washed, so clay, silt and organic matter are out of it. That is what makes it work across four fairly different jobs.

Bedding under pavers and flagstone, screeded thin and even, so each unit sits on full contact rather than on high points.

Joint filling, swept in and vibrated down so the units lock against each other. Joints that are left part-empty are where weeds start.

Mortar, stucco and grout, where a consistent fine grain gives a mix that spreads cleanly and holds together under a trowel.

Sandboxes, play areas and volleyball courts, where washed and fine is exactly what bare hands and feet want. Put it over drainage rather than in a sealed box, or it stays wet for a week after every summer storm.

Where a ditch line and a rock garden change the answer

Two jobs that come up in orders and deserve a straight answer.

A culvert outlet or ditch lining is not sand work. Anywhere water runs with force, fine material is the first thing to leave, and the bank it was meant to protect goes with it. Line a ditch or an outlet with RipRap and keep the sand for surfaces under cover of pavers or turf.

A xeriscape or rock garden bed is a partial yes. Sand is useful as a setting bed under individual stones and slabs, giving you the few degrees of adjustment that make a boulder sit right. It is not the ground cover. Stone or a decorative gravel goes on top, and a fine sand left exposed in a bed will wash into the lawn and the paths.

A 12 by 16 shed pad in Central Massachusetts, layer by layer

A worked example, hypothetical rather than a real project. A 12 foot by 16 foot shed pad on till in Central Massachusetts, built as a compacted base with paver or block flooring bedded on sand.

Base at six inches compacted:

• Area: 12 x 16 = 192 square feet
• Depth in feet: 6 / 12 = 0.5 ft
• Volume: 192 x 0.5 = 96 cubic feet
• Cubic yards: 96 / 27 = 3.56

Bedding sand at one inch:

• Depth in feet: 1 / 12 = 0.083 ft
• Volume: 192 x 0.083 = 16 cubic feet
• Cubic yards: 16 / 27 = 0.59

So roughly three and a half yards of base to six tenths of a yard of sand, and the five percent the sand calculator adds by default takes the sand to about 0.62. That ratio surprises people. Sand is the visible layer and the small one, and ordering it by eye rather than by arithmetic is how a job ends up with a pile left over.

This site publishes roughly 2,700 lb per cubic yard for mason and washed sand, about 1.35 tons per yard, so that 0.59 yards of bedding sand is 0.59 x 1.35 = 0.8 tons, approximately, and 0.62 yards with the five percent is a shade over 0.83. Check the figure in the sand calculator before ordering by the ton.

Topping up joints after the first freeze-thaw season

Jointed sand settles and washes down over the first year, and a Massachusetts winter of freeze, thaw and salt accelerates it. Sweep more in during the spring, wet it down and let it settle, then check again after a few weeks. Doing that once a year keeps edges tight and keeps weeds from finding a seedbed.

When the numbers are set, choose a quantity and a delivery date on this page, and think about ordering base and sand together so they arrive on the days you need them rather than as two separate trips. Delivery is arranged at checkout from your ZIP code, and the driver needs a clear spot he can reach and tip onto. Sand in particular wants a tarp and somewhere sheltered, because a pile left uncovered on a driveway through a wet week is harder to work with afterwards.