Small Piers and Sono-tubes: Two sizes of square pyramids (9 x 9 x 6" Ht. and 16 x 16 x 12" Ht.) work well as deck and basement post supports and blocking up mobile homes. Thrust blocks are a shorter version of the piers, and work well as supports for mobile homes, propane tanks, etc. They serve to keep wood blocking raised above moisture levels and provide a stable base. For larger applications we build a cylindrical Sono-tube support, with 16" diameter tapered base, 9" top diameter and 36" height.