Is a deck foundation built entirely with the deck blocks common or is this not a good way to do this? I'm planning a deck approximately 28' x 18' wooden deck with two tiers. The tiers would just be one step. The deck would be about 12-18" off the ground at its lowest and 24" at its highest. Also, is it real necessary to attach the deck to the house or can it be built up against it without tearing up the siding? I want to remove as many difficult steps as possible but of course want to maintain the integrity of the structure. BTW, this would be deck for my yard. Thanks!