[ATTACH]68326[/ATTACH] I'm trying to add on to an existing deck. If anyone knows it would be greatly appreciated. Dave

Good day everyone. I am embarking on a fairly ambitious project and have a million and one questions but will save you all the drawn out story and focus on the basics. I originally went down the path of a roughly 1200 square foot concrete patio off the back of my walk-out basement. Seems like a fairly straight forward project for a competent contractor however; I have hit a number of major hurdles that have left my confidence shaken. The main concern with the area is the very high water table. I have had 6 potential contractors our to assess and quote and each one of them had a different approach to deal with the water in a climate that sees very cold (-30 degree) winters. So, in no hurry to throw away a pretty good sum of $$ on concrete, I'm now thinking that a ground level floating deck is the way to go. At least this way if the water does create a problem I can lift a few boards and address it. Now, on to the questions. I don't have a lot of ground clearance at the exterior door. There is currently about 2" from the grade to the door threshold. My thought was to make a ground level path out from the door to an area roughly 20 feet out where the space will open up to a fire pit. To the left and right of the ground level path would be a slightly elevated deck, roughly 8". The elevated areas of the deck are straight forward using beam and joist hangers. What is the best approach for the ground level path? I have heard of laying a 2x4 or 2x6 on edge directly on the ground and attaching your deck boards to them. This would work with the low clearance that I have. 1.) Is this an acceptable approach? Can I assume that the decking will move with the freeze and thaw cycles? 2.) The next thing I have to be concerned with is water drainage. My thought is to excavate 6" and try to achieve a 5%-7% grade away from the house. We are in a heavy clay based area so my thought is with that steep a grade the water will follow the clay away from the house. At the end of the deck roughly 20 feet away from the house I will install a French drain the width of the deck, 12" below the excavated depth. The water should follow the grade and drop into the French drain. Is this a feasible approach? 3.) Assuming number 2 is an approved approach, I now have to deal with the back fill of the excavated area. The raised portions of the deck are not a big deal. I can essentially backfill with anything that will provide good drainage down to my clay base. 3/4 washed rock perhaps? The challenge is what to do under the ground level portion of the deck. If number 1 is an approved approach I am going to need a sub base that is compactable. If it is compactable like 3/4 road crush, then it will not have the drainage characteristics that I may required. Perhaps I could move to a 2" shattered rock with a jagged face. I know that would provide drainage but would it provide the compaction that I need? 4.) Yes, an exhausting thread I know but another question has popped into my head. For the raised portions of the deck I would prefer not to have to go with pilings as we have a 4'-6' frost line here. If I'm going with the floating deck concept can I get away with footings? My thought is to dig 12" diameter, 12" deep holes and fill with concrete. I would expand the base of the hole to 14" to prevent the footing from heaving. Would this work or am I stuck with pilings? I appreciate any input you may have to offer. This will an expensive build regardless so I want to make sure I'm on the right path.