Asphalt Millings

Asphalt millings are created when a road milling machine grinds up an existing asphalt surface during resurfacing work. The removed material, technically reclaimed asphalt pavement or RAP, still contains the original aggregate along with residual asphalt binder (bitumen) coating each particle. That leftover binder is what makes millings behave differently from plain crushed stone. Once screened, most suppliers sort the material into a coarser minus 1.5 inch grade for base work and driveways, and a finer 3/8 inch minus or processed grade for a smoother finished surface. Because the source material comes from different roads and mix designs, quality and binder content can vary noticeably load to load. Buyers should ask whether the batch is a consistent, screened product or unscreened mixed millings, since inconsistent gradation makes even compaction harder and can leave lumps of old pavement embedded near the surface.

Millings perform best over a properly graded and crowned subgrade, ideally a compacted layer of crushed stone or crusher run that provides drainage and load support underneath. Skipping this step is the single biggest reason milling driveways fail early. Spread the material in lifts of 2 to 3 inches loose depth, then compact each lift with a plate compactor for small areas or a vibratory roller for driveways and lots, rather than relying on vehicle traffic to do the compacting. Since millings shrink 25 to 30 percent as they compact, plan on ordering roughly 1.4 times the loose volume you calculate from your target finished depth. Grade the finished surface with a slight slope, about 1 to 2 percent, toward a drainage path, because compacted millings shed water rather than absorbing it like open-graded gravel. In warm weather, expect the surface to continue firming up over several weeks as the asphalt binder re-fuses under sun and traffic.

Compared with gravel. Gravel is lighter colored, drains better since it has no binder, and never softens in heat, but it does not lock together into a solid surface the way millings do and tends to washboard and rut under vehicle traffic without regular regrading. Millings trade some drainage performance for a firmer, more asphalt-like feel underfoot and less loose stone tracked indoors.

Compared with new hot-mix asphalt. New asphalt is engineered, smoother, and holds up longer without maintenance, but costs roughly two to three times more per square foot and requires paving equipment and crews. Millings look similar once compacted and cost far less, making them a practical DIY alternative, though the realistic service life is shorter unless the surface is later sealed.

How much do I need to order. Start with square footage times your target compacted depth, most driveways use 3 to 4 inches. One cubic yard covers about 80 sq ft at 4 inches or 160 sq ft at 2 inches. Because loose millings compact down 25 to 30 percent, add 30 to 40 percent extra loose volume to your base calculation, or use a supplier's tonnage calculator to convert square footage and depth directly into tons.

How millings are sold and delivered. Asphalt millings are typically sold by the ton, with bulk dump truck delivery in loads ranging from about 8 to 20 tons depending on the truck and jobsite access. Pricing runs $10 to $20 per ton or $12 to $32 per cubic yard, with delivery adding roughly 50 percent depending on distance and load size. Smaller quantities may be available bagged or by trailer load for tight-access residential sites.