and secured in succession as shown in fig2 and 3 the deck assembly 100 and the deck panels 110 provide a number of advantages the deck panels 110 are easy to lay secure and assemble into the deck assembly 100 because the tongues 130 and grooves 132 assist in properly seating and aligning the deck panels 110 it is only necessary to secure one side of each deck panel 110 with fasteners 5 the cellular structure i e the interior walls 120 and the passages 122 enhance the rigidity and lighten the deck panels 110 the integration provided by the tongues and grooves enhances the strength and rigidity of the overall deck assembly 100 in particular the tongues and grooves distribute weight to adjacent deck panels 110 the unused portions of the fastener holes 142 not directly overlying the joists 20 may serve as water drain holes for the deck 10 the tongue and groove arrangement also provides for improved aesthetics even when the polymeric deck panels 110 contract the tongues 130 prevent formation of gaps fully through the deck assembly 100 also because the tongues 130 extend between the adjacent deck panels 110 the deck panels 110 may be laid with.