[4seasons]

I have a job coming up that we will be installing stepping stones, with grass flush with the tops. As of right now, we'll be excavating out for the base and prepping same as any walkway. My question is if we us a large slab stone (say 4-5" thick) can a person eliminate stone base? If we just layed fabric down would that keep them from sinking? I'm asking because I don't feel 4-5 inches of topsoil is enough to keep grass growing. I don't want it to look like a septic area. No there won't be any irrigation.

thanks,
Bruce

[AZTLANLC]

I think you can do it but I feel like if you area gets some good frosts then it will shift.
Why not get a thicker stone say 7" and prep your base normally then bury 3" that will also help with stability.
If the area is real hot this is what I did with one job last season and the grass looks the same or better than any other section.

Dig area then mix portland with your aggregate and compact like for any other project, set stone and then dig out couple inches of base close to the back of the step install geotextile or filter fabric behind.
Mix top soil with polymer cristals and back fill.

[4seasons]

these stones weigh about 1000lbs or more apiece. Do you think they will still move? I do like the polymer idea, I even have enough to do the job.

[agla]

I'd do it in topsoil. I've done 2'x3'x2" bluestone in loam as stepping stones myself and working for others. Freeze/thaw is less an issue when dealing with stepping stones because they are not very close. A stone of that size does not pitch radically different that the soil around it. I am in an area that is not high in clay. The soil is often very high in sand, so it is not the same as what some of you have to deal with.

I would not bother with the fabric.

[Stonehenge]

If it is clay, so long as the soils aren't freshly backfilled (like around a foundation), I'd still do it as Agla recommends. In fact, we'll be doing it exactly that way on a job in about 4-5 weeks. Though it does sound like Aztlanlc is pretty thorough with his method.

[trees]

We live in a very heavy clay area (although admittedly not much freeze/thaw) and we don't do much other than excavate for the stone and lay a little dust to help with leveling. Never have much of a problem with stones shifting.

[ianc]

I do it all the time using skid sized flagstone pieces - we call it mega-flag around here
the frost will move it up and down - ususally back to the same elevation and if not a quick spud bar adjustment will fix it up

[4seasons]

thanks for all your help guys!
And stay cool out there.