 the railings in the the fencing it in so the post would come up and that would be you know the basis for your supports and that would be your pressure treated lumber and that would be built up through from the substructure and then there are sleeves that go over it in the composite now you can get ones that match your decking or you can go with white and then for the substructure now i am talking about staying this out um here are these concrete i don't know but i put by a foot um blocks that you can buy that you can lay your four by six across for they say it's for um