Gravel Delivery FAQ for Pennsylvania Ground

The building window here is set by the ground rather than the calendar. It opens when the frost has come out and the surface has drained, which is weeks later on the northern plateau and in the mountains than on the southeastern lowlands, and it closes when the ground starts freezing again in late fall. Nothing goes down on frozen or muddy ground. Almost every question below turns up somewhere inside that window, so they are answered in the order they tend to arrive.

The yard calls it 2A modified and the listing says road base. Which do I order?

The same one. 2A Modified is the catalogue name and road base is the generic term the network uses behind it. Local naming runs alongside the AASHTO numbers throughout the listings: 2B and #57 are the same size, and 1B and #8 are the same size. Where a listing carries two names, the product page says so in the size and grading lines. The numbers behind those names come from PennDOT Publication 408, Section 703, which sizes clean stone by AASHTO number and names its own dense-graded No. 2A subbase; 2A modified is the trade name for a 2A-type base with extra fines rather than a specification in its own right. None of that is a certification held here. Match on size and grading rather than on the word, and where a job follows a road-agency or engineering spec, compare that spec against the product page before ordering.

The drive needs two layers. Do I order them together?

As two separate quantities on one order. The base is a compacting material with fines left in, usually 2A modified, figured at its own depth. The surface is whatever the finished job has to be: Driveway Gravel on a lane, Screenings under pavers, 3/8" Crushed Stone for a tighter finish. Run each layer through the calculator on its own, because the depths differ and so do the weights, then put both lines on the same order.

The ground where the pad goes is soft and wet. What now?

Fix the wet before you buy stone. On plateau hillsides that usually means intercepting roof and drive runoff before it soaks into clay on the slope. On glacial ground in the north it often means the water perching above a dense layer, which takes a drain rather than more material. Dumping base stone into mud buys a season at most, because the fines pump up through it by the second spring. Where the subgrade cannot be dried out, a separation fabric under the stone keeps the two from mixing; it is not a catalogue item here, so it comes from a local landscape supplier rather than onto this order, and the depth goes up rather than down.

What goes under a gravel drive, and in what order?

Bottom upwards: sound subgrade with the soft and organic material taken out, Fill Dirt if the grade has to be made up, then compacted 2A modified in lifts, then a surface course. On wet ground a separation fabric goes between subgrade and stone. Each lift gets wetted and compacted before the next, because a layer that was never compacted is a pile you drive on rather than a base. Crown the finished surface and give the water a ditch to leave by.

Spread three inches deep, a single cubic yard covers what?

About 108 square feet. That figure holds for any material, because it is volume rather than weight: a yard spread three inches deep covers the same ground whether it is stone or mulch. Halve the depth and you double the coverage. What changes between materials is the tonnage, since a yard of screened topsoil runs about 2,200 lb and a yard of rip rap about 3,100 lb.

When in the Pennsylvania year is this job best built?

Between the thaw and the first hard freeze, with a dry spell in it. Base, driveway and paver work runs from spring, once the ground has thawed and dried, into late fall. In the lake-effect snow belt and on the high plateau that start date arrives noticeably later. Wet spells and rain on snow are the worst windows of all on hillside ground, since that is when slopes are most likely to move. Decorative work and mulch are far less fussy about it.

When does the job need an engineer rather than a counterman?

Anything structural, anything in or beside a stream, and any retaining wall above a modest height. Stream bank and culvert work often sits under permitting, and bluff setbacks apply along the lake shoreline. Hillside lots with clay-rich soil, and ground over old underground mine workings, are both worth a professional opinion before a heavy pad or wall goes in. Nothing here substitutes for that, and Contact will say so rather than guess.

The rest of the job sits on two other pages. The material calculators handle rounding, a lane that changes width and the tonnage arithmetic, one material at a time. The delivery page covers the checkout screen, the tip and the drop spot, and it is where a change of mind goes: short by a ton, buy that ton on its own rather than reopening a booked load. The refund and order-change policy is published there.

Who operates Pennsylvania Rock Supply?