Gravel Delivery Questions, Taken in Buying Order

Ask for processed gravel at a Massachusetts yard and you get a one inch minus blend of crushed stone, gravel and binding fines. Order road base from a national catalogue and the material that turns up is the same thing under a different label. Most of what follows comes out of that gap between the name your plan uses, the name the yard uses and the name on the product page.

The questions run in the order they normally come up, from picking a material to the week of the year the ground will take it.

Picking a material for ground that is mostly till

Is the one-inch-minus processed gravel here the road base my plan specifies?

In practice, yes. Processed Gravel is the catalogue entry, one inch minus, a graded mix of crushed stone, gravel and binding fines. Local suppliers say processed gravel far more often than road base, and some list a similar blend as dense grade or 3/4 inch dense grade. Work from the size and grading on the product page rather than the trade name, and the match is straightforward. The same applies to loam, which is what nearly everyone here calls screened Top Soil, and to pea stone, which is the local name for 3/8 inch natural pea gravel.

A town specification that quotes a section number is doing the same job. MassDOT names base layers by material section: M1.03.1 is processed gravel for subbase, M2.01.7 is dense graded crushed stone for sub-base, and M1.03.0 is gravel borrow, and those are the sections town road standards call for under streets and sidewalks. The section number describes the material rather than certifying a load, so compare it against the size and grading on the product page.

I need a base and a surface. How do I plan a job with two layers?

Treat them as two separate orders on the same delivery. Work out the base layer in its own calculation, work out the surface course in another, then add the tonnages. They are different materials at different weights, so a single calculation cannot cover both. On a drive, that is usually Processed Gravel or Crusher Run underneath and Driveway Gravel or a crushed stone on top. On a patio it is a compacted base with exactly one inch of bedding sand over it.

The site is soft and wet. Do I go ahead or wait?

Find out why it is wet first. Across Greater Boston, MetroWest and the Worcester plateau the dense lower till drains slowly and perches snowmelt near the surface, so ground can stay soft for weeks after the thaw without anything being wrong with it. Silty lake-bed soils on the Pioneer Valley floor behave the same way, and low ground around the southeastern swamps and bogs holds water after heavy rain.

Material spread on soft subgrade pumps and ruts instead of compacting, so nothing you put down will hold. Either wait for it to dry, or excavate the soft material out and build back up in compacted lifts. Cape Cod and the Islands sit on deep outwash sand that sheds rain quickly and firms up sooner, which is why the same March week is workable there and not inland.

Driveway layers and the numbers behind them

Building a drive up from bare subgrade: which layer lands first?

Subgrade first, and it needs to be firm and shedding water before anything else happens. Then the compacting base, processed gravel or crusher run, placed and compacted in separate lifts rather than one thick pass, because a plate compactor only reaches so far down. Then the surface course, driveway gravel or a crushed stone. A new drive is generally built around six inches of material in total. Crown it or give it a fall so water leaves rather than sitting in it, which is what turns a good base into potholes by March.

One yard of stone, three inches deep: how far does that reach?

At three inches deep, one cubic yard covers about 108 square feet. That is the figure to hold in your head when someone tells you a number over the phone. Halve the depth and you double the coverage; double the depth and you halve it. At two inches a yard covers around 162 square feet, and at four inches around 81.

The month the ground will take a base

Is there a right month to start on Massachusetts ground?

Base, driveway and paver work runs spring through late fall. Frozen ground takes no compaction, so winter is for measuring rather than spreading. The awkward edge is early spring, when the thaw leaves till and silt soft, and the season starts later and finishes earlier in the Berkshires and the western hilltowns than it does near the coast. The Cape and the Islands get the mildest winters in the state, though nor'easters make late autumn and winter rough for work near the water.

At what point does a wall or a bank stop being a tonnage problem?

Anything holding back soil or water at height, anything carrying a structure, and anything on a stream bank or a shoreline where a permit is likely. A segmental wall past a couple of courses, a culvert outlet, a bank armored against nor'easter surge: those are design questions, and the quantity is the easy part of them. Take the design to a local engineer or your building department, then come back with the layer and depth figures and size the material from those.

Two sets of questions are answered better elsewhere on this site. Coverage at other depths, rounding, a wedge or a curve and the tonnage arithmetic are what the material calculators do. Everything from the checkout screen onward belongs to the delivery page, including the fix for a load that runs short: a fresh order covering the balance, rather than an alteration to one already booked. The refund and order-change policy sits with it.

Is the one-inch-minus processed gravel in the catalogue the road base my plan specifies?

How much ground does one yard of stone cover at three inches, and at four?

Building a drive up from bare subgrade, which layer lands first?

Who operates Massachusetts Rock Supply?