This grass is being installed next to a hard concrete edge

But, you may wonder, why do I need to install a sub-base? Why can’t I just install my artificial grass on the soil as is? The answer has to do with some basic scientific principles – expansion and contraction. Soil naturally expands and contracts over time depending on climate. For natural grass this presents no problem because it is growing in the soil. For artificial grass, however, such expansion and contraction can result in buckling, wrinkling and an uneven surface.

This grass is being installed next to a hard concrete edge

The solution for preventing this is to replace the soil with a substance that will not expand or contract. A proper sub-base comprised of either class II road base (also known as crushed miscellaneous base or CMB) or decomposed granite will provide an excellent foundation for your artificial grass and will help ensure you get the most out of your investment.