I'm looking to build a 12 x 12 ft free standing deck behind our house and a question comes up: floating or not? Wife wants floating for cost, but I'm leaning towards burying 4x4's past frost line (42" in Michigan) and creating a non floating deck. I believe it's more stable and will last longer without having to re-level. Now, I could make a floating, but I believe it would take quite a bit more excavation to create a level playing field. My fear is, over time, things would shift and we'd end up with a sloping deck from sinkage or shifting.
Project Guide: Building a Ground-Level Deck
This link shows how to create a floating deck from home depots website.
Finally to my question: The floating deck on the web shows them pouring a 8" dia hole-12" deep for a footing and not worrying about the frost line. Isn't this wrong???? Doesn't this go against the whole reason of going below the frost line??? Wouldn't this shift???
It just seems wrong and too cheap to last.