A falling-down grape arbor is forcing me to reprioritize home projects and move the small backyard of my Baltimore rowhouse to the top of the list. I'm mulling a patio using some sort of pavers to cover much of the 16 foot wide X 24 foot long space. I had thought that the best route was a gravel base, with sand and then pavers of it, in part because there's an old grape vine I'd like to preserve and figure that leaves more ability for moisture to get to the earth. (I will in any case, leave atleast a few feet of open space around the vine.)

But the mason I'm talking to says he very much prefers doing a concrete base, and that this will allow me to pull my car into the space if I want to (as some folks do in my urban neighborhood when they will for example be out of town for a few weeks and don't want to leave it on the street for that long).

I'd like that option, but not at the cost of less problem prone patio. Is there more likelihood of freeze heaving with a concrete slab? (Baltimore's not New England or Minnesota, but we do get hard freezes in the winter and frequent thaws.) ARe there other advantages or disadvantages I should consider?

Thanks for your help.