My cat recently had a UTi, and unbeknown to us has ruined a good portion of my living room carpet. I have tried my best cleaning it and it still smells, and is discolored. There is nice hardwood flooring underneath carpeting, so I'd love to just rip it up. I know enough to do any resurfacing to the flooring it needs, but the problem is the previous owners expanded the LR into what was a carport. And just left/added concrete as flooring, and filled in the gap. So LR is half hardwood/cement. There is a noticeable dip from HW(higher) to concrete(lower), but from what I can tell only 1/4", maybe. So what would be my options in adding new hardwood to line up with the old, and how can I handle the height difference it would create? And what is the thinnest type of underlayment can be used for moisture barrier?