What Kind of Oil Can I Spray Between Rock Layers to Keep Layers in Place?

Rapid-Curing Liquid Asphalt

• To a driveway base, based on an evaluation of the soil, pavers may apply a coat of rapid-curing liquid asphalt oil with a grade of 250, 800 or 3,000 based on a blend of selected asphalts and light petroleum solvents. The oil solvent quickly evaporates and hardens. Pavers spray the oil with a sprayer attached to an oil truck. Rapid-curing liquid asphalt is highly flammable with a flash point or flammable point of 80 degrees Fahrenheit.

Medium-Curing Liquid Asphalt (MC)

• The soil may suit medium-curing asphalt (MC), also a blended asphalt but slightly less flammable than rapid-curing asphalt. The MC-70 grade has a flash point of above 100 degrees Fahrenheit. Grades MC-250, 800 and 3,000 are flammable at a temperature of 150 degrees Fahrenheit. To keep the layers in place, pavers spray oil over the layers of stone followed by a second layer of 1/4-inch to 1/2-inch colored stone to fill the voids.

Slow-Curing Liquid Asphalt (SC)

• The soil evaluation may require slow-curing asphalt, which ranges from grade SC-70 to SC-3,000 with a flash point starting at above 150 degrees Fahrenheit. Maintain an even layer of loose stones to ensure the environment does not leave layers of oil and bare areas over time. With proper maintenance, an oil and stone surface can last 10 to 12 years.

Tips

• The oil treatment should not begin until an assessor confirms a solid foundation with suitable subsoil conditions to determine the grade that's right for the driveway. Oil will disappear into porous soil through the stones. The assessment of the oil-gravel combination prevents the driveway from cracking, sinking and settling unevenly under the weight of cars.