I have an exisitng 25 yr old metal patio cover I want to tear down and replace with a nice wooden one. I currently have an uneven concrete patio 4x4 squares that have sunken down in certain spots. When I lay the footings for the new 4x6 posts should I build the footings underneath the concrete or raise the concrete footings above the level of current concrete? down the road I plan on tearing all this old concrete out and laying a new pad. I just want everything to come out level.