TuffBlock is the world’s fastest growing foundation method for a range of home improvement projects, including raised or low-profile decks, walkways, cubby houses, and much more. TuffBlock removes the need for digging holes and pouring concrete, making it the easiest and most versatile foundation system on the market.- Accepts 3.5" x 3.5" or 4" x 4" Posts- Accepts 1½" - 2" Joists & Bearers- Each TuffBlock is load rated for 1700lbs