[John LaPointe]

I am working on a project at a school where the design calls for flagstones to be laid within a concrete patio. I have a number of concerns about the finished product. First, I will be cutting into the patio with a partner saw and will use a sawsall to finish the cuts. During a practice run on a different job I ran into the problem of the surrounding concrete cracking when trying to extract the cutout piece. During the practice run I did not finish the cuts with the sawsall, so my hope is if I complete the cut, breaking out the cutout piece will not cause cracking.
My intention is to set the flags slightly (< 1/16 - 1/8") above grade for drainage. Will this be a hazard for kids or will it be slight and insignificant?
The next major issue is securing the stones to deal with heavy traffic. I intend on using 2-3" stones which will be weighty and hopefully set nicely. I will excavate the hole and use 4" of Traffic bond then one inch of sand. To secure the stone I plan to use a polymeric sand (after reading much discussion on this forum). Gaps will likely be from 1-2". Any thoughts on these specs?
Finally, I am wondering how far apart I should space the flags in order to not compromise the surrounding concrete.

Any thoughts will help - the principal is beginning to get anxious for me to start - winter is fast approaching in Wisconsin.

Thanks for your help

[skahuna]

I think you need to remove the concrete in question and repour at the right height and mortar the flags in i think the concrete will crack even if they're a couple of feet apart
if you really want to try it you can rent a diamond blade chainsaw to finish the cuts

[John LaPointe]

I understand that I am leaving the concrete quite vulnerable. Perhaps, even if it works in the short term it will crack and break in the long term.

The flags are meant to be a transition from the patio out into the lawn, with more flags as you move off the patio. Maybe I should remove a section of the patio in some sort of design and replace it with flagstone. This could also act as an interesting transition but with less risk.