The depth of decomposed granite depends on the load the surface will support. For a vehicle driveway, install decomposed granite six inches deep. For pedestrian areas, use three inches, and for decorative surfaces, one inch will suffice. Heavier loads require thicker layers to ensure stability, drainage, and longevity, while lighter uses can maintain their appearance with less material.
One cubic yard of decomposed granite covers 54 square feet when laid to a six-inch depth. This conversion is derived by dividing the volume in cubic feet by the depth in feet. The calculation is fundamental for project planning because it converts three-dimensional volume into the two-dimensional area of coverage. Due to potential settling and compaction after installation, pros recommend an extra 15% to ensure the installed layer meets precise design requirements and maintains robust stability over time.
Determining whether a base layer is necessary for decomposed granite installation requires careful assessment of your project needs. A base layer of crushed rock or gravel provides essential support, improved drainage, and enhanced stability. Utilizing a solid base improves the overall structure by absorbing weight, reducing erosion, and extending the life of the surface. Additionally, a properly compacted base layer minimizes shifting and settling, ensuring that the decomposed granite remains evenly distributed and effective over time.