Gravel, Stone and Soil for Allegheny County, PA
What base stone holds up on a driveway in Allegheny County? For most jobs, it is 2A modified. Pennsylvania Rock Supply delivers gravel, stone and aggregate delivery in Allegheny County, PA, by the ton, straight to your site. The ground here is silty and clay-rich, weathered from shale and sandstone, and much of it sits on hilly ground cut by steep valleys. That ground tells you which material to order before you ever grade the pad.
Materials Delivered in Allegheny County
Order by the size the job needs, from coarse to fine. The names below are the ones local yards use.
Give 2A modified the most thought, because it carries most of the work here. It is a 2A-type base with extra fines added, and it is the trade name for that mix. Local yards still say 2B for #57 and 1B for #8, so you can order by either name.
For the finer end of the range, order Top Soil screened for lawns and final grading, Mason Sand for brick and block mortar and paver joints, or River Rock for decorative beds, borders and dry creek beds.
Ground Conditions Across Allegheny County
Plan the work around the working season. Base, driveway and paver work runs from spring, once the ground has thawed and dried, into late fall. Long wet spells and rain on snow are when hillside ground is most likely to move, so timing a delivery matters as much as picking the material.
The ground itself is flat-lying shale, siltstone, sandstone, claystone and coal beds weathered into silty and clay-rich soils. Many communities sit over old underground coal mines. Heavy rain and snowmelt run down steep hillsides, and water soaking into clay layers on slopes is the main landslide trigger.
That makes drainage the first decision on a hillside lot. Where roof and drive runoff is sent decides how the base holds up. Use clean stone such as 2B for drainage behind walls, and compact 2A modified in lifts so water does not sit in the fines and soften them.
Winter brings repeated freeze-thaw cycles, and clay-rich soils that stay wet soften and heave. A thin or poorly drained base breaks up under that cycle. Frost depth is commonly about 36 inches, set by each municipality, so check with your local building official before you build.
Delivery Across Allegheny County
Order online and pick your delivery date at checkout. You size the load by the ton or the yard, and the site calculator does the arithmetic for you. A dump truck then brings the material to your site and places it where you point.
Coverage runs across the county, including Pittsburgh, Bethel Park, Monroeville, Allison Park, West Mifflin, McKeesport, South Park, North Versailles, Glenshaw, Carnegie, Oakmont, Clairton, McKees Rocks and Coraopolis.
On a hillside lot, think about where the truck can turn around and where the pile should sit. Keeping the pile close to the work, and off any slope that drains toward the house, saves you a second move later.
Choosing the Right Material
Allegheny County sits in the Western Pennsylvania plateau hills, on silty and clay-rich soils over shale and coal beds. Washington County shares that same ground zone, so the material choice is similar and the comparison is really about the project: a driveway base there takes the same 2A modified, and drainage stone takes the same 2B.
Westmoreland County spans more than one zone, reaching the North-central high plateau and Allegheny Mountains, so projects there can sit on steeper mountain ground where clean drainage stone and slope armoring carry more of the job. Butler County also spans zones, with glaciated ground in its northeast and northwest, which can change how a base drains and compacts compared with the clay-rich hills here.
Across all four counties, the rule holds: 2A modified for a compacting base, clean stone such as 2B for any job that has to move water.
Order Gravel, Stone and Soil in Allegheny County
Pennsylvania Rock Supply delivers bulk gravel, stone, sand, topsoil and mulch across Allegheny County, from Pittsburgh and Bethel Park to Monroeville, McKeesport and Coraopolis. Pick your material, size the load by the ton or yard, and choose a delivery date at checkout. Order online when you are ready to build.