Sandstone Ballast Blocks; Split-face Random walling 200mm thick. Pound for pound this is very good value stone and highly versatile making everything from large structural walls of half a dozen styles to garden retainers to solid stone stairs. Its thick enough to split and double your square metres. $155 per m2, Most pieces are already corners and caps. Solid blocks cut into a difficult style.Sandstone ballast blocks cut into a unique style tight join dry pack wall.Ballast cut into to cladding to ensure the styles matched.Sandstone ballast blocks split into 100 thick cladding and cut into a unique style tight join dry pack wall. Ballast Blocks - random square.Sandstone ballast blocks cut into a tight join dry pack wall.Ballast Blocks - random square - regular joins.sandstone ballast blocks cut into a medium join dry pack wall.