I have a rough concrete slab roughly 10x10. My question is can I build a wood deck over this? The space between the bottom of the door to the top of the slab would only allow me to use a 2x6 as a ledger and 2x4's as joists. If I space the 2x4's closer together then normal will this work. I plan on building the deck just longer than the slab so I can put two 4x4's in the corners opposite the house. Thank you.