WARD WORKS Setting Posts 1. Dig or auger post Holes: The 4"x 4" Vinyl Posts require 10° DIAMETER HOLE, and must beat least 30" BELOW GRADE. (See Fig 2) In frost regions, the post Holes should've deep enough to extend below the frost ling 2. Concreteness according to manufacturer's specifications. Fill the bottom of the hole developed 24" from theatrics. 3.