My experience is that a serious concrete footing vs. chat base or other answer is best for longevity and fewest future cracks. If the concrete "form" under the steps is deep enough you should have no problems. Flagstone risers under flagstone treads look best, no question. Hortster

Dear Friends, I'm building a 8 feet radius round flagstone patio on my sloppy backyard (As pictured, DIY). I dig off a foot and half on the left, the front and right side of the patio will still be above the ground. Originally my design is to build a base with 5 inches of crush stone base, surrounded by retaining wall block (left, front side). Mix about 2 inch of mortar and stick Flagstone (already bought 2 tons stone about 1.5-2" thickness) on top of the base and wall. I am hopping the mortal will hold the stone well so it won't shift off the slop. As I read more on the internet and I have the concern the patio will end up crack for the way I lay it (people mentioned different expansion ratio of the mortar and stone etc). Here I would like to hear some advises for how should I continue. 1. Am I OK to continue my original plan. Will cracking really a concern in Atlanta GA area, the overall weather hear is mild with a few freezing days. I'll try to compact the base as much as i can. Maybe increase the mortal layer to 3 inches would help? Should I build a rough concrete patio enforced with metal bar, say 3 inches thickness. On top, lay the flagstone with mortar. Will this keep the patio in shape better than plan 1 above. Should I be better off dry laid flag stone. It actually take less effort to do. Add Stone dust on top of pave base and do dry laid. I am worry the rain water will end up wash off the base and fillings in the crack. It will be hard to keep the stones intact over the long run. Really appreciate your comment to guide me further.

Basically, I don't know what I want, other than to fix the drainage issues. I'm just not sure logistically if option 2 is even an acceptable/appropriate option. I basically have been asking people what they would do to fix how it's settled. Budget is on the basic side as we still have to regrade and replant the front and fix the leaking cracks in the basement. I don't really want to excavate the front and reparge the foundation wall because we're in a townhouse, so that gets really complicated. And there's not enough leaking to need an interior French drain. Was hoping that regrading the walkway and the dirt/plants would be the first thing to try as it's not crazy expensive. I could wait on the walkway and just do the regrading and plants, but that seems a little silly.... The whole row of townhouses has had water issues this past year and no one has excavated anything. Companies want $20k to do that. The HOA is working on implementing some kind of drainage solution for the entire row, so I also don't really want to excavate till we see if that solution helps our basement. I hate basements. :-\

You have all confirmed the niggling doubt that followed my quick ’Ah ha” idea. Knew I could count on your wise input. Its actually just the awful cracks that bother me, Cement on the other has never been an issue for me, though, sure, all of it in flagstone would be the ideal. Because of the addition of brick across the pool, I’d not want a third element, such as pavers or a different design on the cement. Due to that brick and the nice view, I never much noticed the cement …until the cracks .I can be ‘a’-retentive on somethings while S’good nuff on others. Ive always like lightly dimpled concrete, but thats probably just due to wear and not a design?