How thick should really my concrete garage base be? With standard soil problems, 4" (100mm) concrete over four" (100mm) cleanse effectively compacted hardcore blinded with 2" (50mm) perfectly compacted sand or ash needs to be enough. The perimeter should be thickened into a minimum amount 10" (250mm) by 10" (250mm), https://rylaniymao.ltfblog.com/7993945/foundation-info-for-brand-new-concrete-garages