2A Modified, Gravel and Stone Delivered Across Pennsylvania

Pennsylvania Rock Supply offers bulk gravel and aggregate delivery across Pennsylvania, and the material most Pennsylvania buyers start with is 2A modified. That is the crushed stone with the fines left in, and it compacts hard enough to carry a driveway or a shed pad. Base depth depends on what is under it. Ground across the state runs from glacial till in the north to limestone valleys and red shale in the southeast, and each one drains and settles differently. Pick the base material to match the ground, then build up in lifts.

Materials Delivered Across Pennsylvania

Yards still sell by the older Pennsylvania names alongside those numbers: 2B for #57 and 1B for #8.

2A modified is the standard Pennsylvania base stone. It is a 2A-type base with extra fines added so it locks up tight under a plate compactor or a loaded truck. Order it for driveways, parking pads, and shed and patio bases. If someone asks for crusher run for the same job, they usually mean 2A modified.

Below that, the clean stones handle water, and the fine materials handle bedding and finish work.

Rip rap is sold by R-number here. R-4 suits ditches, and the larger R-5 to R-7 sizes go on banks and streambanks. For a base under pavers, the choice is usually 2A modified first, then a thin bedding layer of screenings or washed sand on top.

Ground and Climate Across Pennsylvania

Ground changes sharply across the state, and the drainage problem changes with it. Water perches over dense glacial till in the north.

Timing follows the same pattern. The working season runs from spring thaw into late fall in every zone, but heavy snow is a bigger factor in the lake-effect belt near Erie, in the Pocono Mountains and the glaciated north, and in the mountains than it is in Southeastern Pennsylvania.

Frost depth is set by each municipality, and it carries the base-depth reasoning here. It runs from 30 inches in Philadelphia to about 42 inches near Erie, in the north and in the mountains, with about 36 inches the common figure in between.

The zones and what they mean for your order

• Southeastern Piedmont and Delaware River lowland: Loamy soils over schist and gneiss on the uplands, red shale and sandstone in the lowlands, and limestone valley soils that weather to heavy clay. A narrow strip along the Delaware River is loose sand and gravel. Frost is about 30 to 36 inches; the City of Philadelphia uses 30 inches. Heavy clay drains slowly, so a compacting 2A modified base with a clean stone edge drain suits it.
• Great Valley and Ridge and Valley, including the anthracite coal region: Long sandstone ridges with thin, stony soils and valleys floored by shale or by limestone and dolomite that weather to clay. Old strip mines and waste piles break up ground in the coal fields. Frost is commonly about 36 inches.
• Glaciated northeast and northwest: Stony till over shale, siltstone and sandstone, often with a dense, slow-draining layer not far below the surface, and sand and gravel in many valleys. Frost is commonly 36 to 42 inches. That dense layer is why water sits, so 2B stone in a French drain does more good than piling on base.
• Lake Erie plain: Glacial till and old lake and stream deposits of sand and gravel over shale and siltstone, laid out in low ridges running parallel to the lake. Frost is commonly about 42 inches. Bluff recession is limited to the Erie shoreline, while stream bank scour and ditch washouts happen inland too.
• Western Pennsylvania plateau hills: Flat-lying shale, siltstone, sandstone, claystone and coal beds weathered into silty, clay-rich soils on hilly ground cut by steep valleys. Many communities sit over old underground coal mines. Frost is commonly about 36 inches. Landslides are most common in the southwest.
• North-central high plateau and Allegheny Mountains: Sandstone, siltstone, shale and conglomerate under thin to moderately deep, stony soils on broad uplands and wide ridges, cut by deep, steep-sided valleys. Coal beds and old mine ground occur in parts of the zone. Frost is commonly 36 to 42 inches, with the deeper figures in the mountains.

Where We Deliver in Pennsylvania

Delivery covers the whole state. Dump trucks run into Philadelphia County, Allegheny County, Montgomery County, Bucks County, Delaware County, Lancaster County, Chester County, York County, Berks County, Lehigh County, Westmoreland County and Luzerne County, along with the counties between them.

That reach takes in the regions as they actually differ: Southeastern Pennsylvania, the Lehigh Valley, the Pocono Mountains, Northeastern Pennsylvania, the Northern Tier, South Central Pennsylvania, Central Pennsylvania, North Central Pennsylvania, Northwestern Pennsylvania and Southwestern Pennsylvania. The material is the same in each, but the ground under it is not, which is why the order changes from one end of the state to the other.

How to Order and Size a Load

Ordering happens online. Choose the material, then set the quantity by the ton or by the yard, whichever suits how you are planning the job.

At checkout you choose a delivery date, and the truck arrives with the full load. For a driveway or pad, plan the base as 2A modified and the drainage as 2B or #57 where water needs somewhere to go.

Order 2A Modified and More Across Pennsylvania

Pennsylvania Rock Supply delivers bulk gravel, stone, sand, soil and mulch across the state, from Philadelphia County to Erie County and everywhere between. The ground differs by zone, so tell us where the load is going and choose the material that fits it.