A gravel driveway represents a practical, affordable choice for a rural home set back from the street, but it's also higher-maintenance than a paved surface. Binding the gravel with hot liquid asphalt offers the benefits of gravel while stabilizing the surface and increasing durability. The process of binding each layer of stone calls for specific equipment to handle the material safely and effectively.
Stabilize the subsoil of the driveway site with a roller machine. Scoop the first two-inch-thick layer of 3/4-inch gravel with a shovel and spread it over the site with a rake.
Spray an even coat of hot RC-250 liquid over the gravel with an asphalt heater and sprayer, working from one end to the other. RC-250 is named for its rapid curing properties. The material is a blend of asphalt and petroleum solvents. The petroleum thins the asphalt so it goes further and is easier to handle. As it hardens, the petroleum evaporates so only the binder remains.
Shovel an additional four-inch-thick layer of 3/4-inch gravel over the oil, and rake it even, or add this layer of gravel with a spreader truck before the hot oil cools. Drive over the gravel with the roller machine several times until the gravel settles and no longer shifts.
Repeat steps 2 and 3 so there are two layers of gravel and RC-250.
Spread a four-inch layer of small gravel measuring between 3/8 inch and 3/4 inch. Rake this top layer into a slight crown so the sides are lower then the center of the driveway, for drainage.
Drive the roller over the gravel, and block it off from traffic for two days. Once the RC-250 sets, the bottom two layers of gravel will harden into a solid base. The surface gravel will remain loose, but easy to maintain. Plan to rake it into a crown every few months as daily use disperses the rocks.