The ¾ DB clean stone is one of the most important components of a French drain system. Its name comes from its ¾ inch dimension, the fact that all the stones are calibrated to the same size ("clean"), and the DB certification which confirms that it is free of pyrite.

Why is pyrite-free certification essential? Because pyrite, in the presence of moisture, can swell and cause cracks in the foundation, damage the concrete, and create water infiltration that is costly to repair.

Why do the stones all have to be the same size? The fact that they are uniform prevents them from interlocking and becoming completely compacted. This allows water to always flow freely through the stone to efficiently reach the French drain, without ever stagnating against the foundation. The result: an efficient drainage system, a protected foundation, and a drier, more durable basement.