I am making a flagstone patio around a large firepit I just constructed. The ground is semi-solid but it all had thick grass over it until about a week ago. I am planning on putting flagstone right up to the lip of the firepit - it won’t be laid tight but all of them will have an inch or so between them. Should I put gravel down first? Or just sandy soil and then lay them down? The land around the firepit is level, but there is a decent slope grading down to the level spot. I will also say that there is a brand new drainage from the foundation that runs adjacent to the now graded patio area. This is what spurred the idea for the firepit, the whole area was torn up from the bobcat digging the drainage - I decided to make the area into a patio because it was in a perfect location. Now I just don’t know if I need to drain under the flagstones.
If you want it to stay nice and even, you need to set up a good base of stone and stone dust under the whole area, really. If you don’t care about unevenness and tripping hazards, just go ahead and lay it down. Just putting an inch of gravel or loose sand around it is not going to get the job done. You need to excavate out about 6 inches and put down 3 inches of stone, some landscape fabric, and then “slag” or “pack” which is a combination of stone dust and stone that packs down hard like cement.
If you lay the stones to have a slope to drain water, and then there is a pathway for that drained water to go offsite, then you should be okay.
How big is the area to be covered with stones? A small area shouldn’t need underground drainage. How permeable are the underlying soils?
I had a little trouble following your description. Could you elaborate on this :“there is a brand new drainage from the foundation that runs adjacent to the now graded patio area”?