Framing and Sub-Flooring - Raised floor 5" on a slab

We about to close on a house in a couple days. The concrete slab floor in the master bedroom (11'x21') is disrupted about half way through with an annoying 5" step up. We want the whole floor to be one level. Our options seem to be to fill with concrete, or raise the floor with timber joists & plywood. We decided [pending other options] to go with the raised timber floor. I haven't been able to find any good solutions on the web on how i might go about doing this most efficiently/effectively. Do i rip down treated 2x6's and run them directly on the slab. Do I lay flat treated 2x4's then run vertical 2x4's. Lastly, what hardware would I use to fasten the solution together. Suggestions or links to references very welcome and needed. Thank you in advance! Kyle

I assume this room is in the basement. I would lay down some tar paper or vapour barrier and rip down treated 2X6 and run them over the tar paper, insulate (preferably spray foam), and cover them with ½” tongue and groove plywood. At this point you want to be 1.125” above the elevated slab. I would then cover the remainder of the elevated slab with basement sub flooring. They come in 2’ X 2’ X 1.125” to ½” (plywood on top and plastic insulation on the bottom) and you can get them at HomeDepo. This way you’re not losing head space. You can see some examples at Basement Flooring with Barricade Subfloor Tiles (http://www.ovrx.com/basement-flooring.html). Just screw it together and run the joists vertically. You don't need any special hardware. Hope this helps.