I've heard so many different ways I've what to do with existing deck posts when laying a patio higher then the original footings. I've heard...

Wrap the post with expansion material and caulk. This I was told will allow the post to come out if it ever needed replacing. These are nailed in now with the post sleeve that is cemented in the footing. Are they suppose to remove the nails prior to laying the cement? Is this feasible?

I've heard just wrap it with plastic and supposedly the water won't get in it. Pretty lame.

I've heard put cement right up to it. I know how well that works for fence posts...it doesn't.

Another which sound the most plausible was the existing footing would be increased in height and temporary posts would be placed. The original posts would be cut down to fit and then placed on top. How truly accurate can someone get the height of the concrete around the post and the new patio? Is this overkill?

I think I know too much about concrete to make this job seem too hard, and I don't know enough to do it ourselves.

I've heard from some very consciousnesses people here that know there stuff. Please guide me in knowing what are the best practices and which ones I should just run from.

BTW, what is the best slope ratio 1/8, 3/16, 1/4, 3/8? The patio will extend out 18'.