Floors are almost always after the steel has been

Floors are almost always after the steel has been erected and especially in the winters up north....they'll pump in heat even first to thawl the ground. Also it prevents a ton of repairs from steel beams and so on being dropped. Take this from a journeyman iron worker that put up every damn Wal-Mart, Target, Bestbuy etc etc in Minnesota year round. Hope this helped.