rebuilding a patio cover
 

I'm thinking about rebuilding a patio cover on a house I just bought. The patio cover that is up is really built poorly. The problem that I'm having is can I mount new posts on not level concrete slab.

Post some pictures.
Think about it, just cut the post differant lengths.

Search these forums, there are a few threads on folks who have done this. Some have fastened to the slab, others have cut the slab out and poured a deeper footing. Your local code matters here. My local code for example says the slab must be at least 3.5" thick in order to attach anything to it.

rebuild porch ideas
 

hear is some photos on the current patio cover.

You can if you want it to look bad and be structurally unsound.

I suggest you break the slab at the footings and pour new ones that are level.