Abstract: The deck block has is made of plastic by a roto-moulding process. The deck block has a truncated pyramidal shape with a flat top plane, a hollow center; a uniform wall thickness; a central vertical post socket and four joist slots extending horizontally from the post socket at a right angle with each other. The deck block has a multi-wall pillar therein extending between a bottom surface of the post socket and a bottom plane of the block. This pillar is made of four vertical hollow oval-shaped columns that are arranged in a circular array under the post socket for reinforcing the bottom surface of the post socket. In another aspect, the joist slots have protruding lips on each side thereof, for enlarging a top surface of the block and for reinforcing the joist slots.

Abstract: The deck block has is made of plastic by a roto-moulding process. The deck block has a truncated pyramidal shape with a flat top plane, a hollow center; a uniform wall thickness; a central vertical post socket and four joist slots extending horizontally from the post socket at a right angle with each other. The deck block has a multi-wall pillar therein extending between a bottom surface of the post socket and a bottom plane of the block. This pillar is made of four vertical hollow oval-shaped columns that are arranged in a circular array under the post socket for reinforcing the bottom surface of the post socket. In another aspect, the joist slots have protruding lips on each side thereof, for enlarging a top surface of the block and for reinforcing the joist slots.