Double faced and Boxed Post w/under-pinning: the runners (rails) on this fence are sandwiched between two sets of pickets. The post are boxed in to hide them from view. This allows both neighbors to share a fence without having a “back side”. This style fence may require additional support due to its weight. Under-pinning utilizes a pressure treated board to fill gaps that occur due to uneven yard surfaces or to prevent animals from entering or leaving the yard.