Basically, I'm planning on laying a dry-construction flagstone area, and have some questions. I've posted a handy-dandy picture for reference:

I understand that getting a good, proper and level sand bed is a very important part of the process, so in my picture, I'm showing roughly where I want the flagstone patio area to be, and have different colors referencing how I plan to retain the sand bed area.

One big thing you'll notice is that I have a concrete sidewalk running along one end, and I would rather not have to deal with busting it up/removing it. This may not be an option, so I'd love to hear opinions.

One thing you cannot really see on the far left side of the picture is that I have 4 or 5 steps coming down from a raised deck to meet the sidewalk where the PURPLE line is. That will be one edge of my sand bed.

The RED line that runs along the bed with hydrangeas will be another border, but the loose paving stones in there now will be replaced with a combination of that steel edging stuff from Home Depot and stones.

The next border is a tricky one -- for the BLUE line, I was planning on lag-bolting some sort of L-bracket across the length of the side walk in combination with some sort of brick/mortor deal.

The GREEN line border will be against the white retaining wall.

Finally, the YELLOW line will be the Home Depot steel edging/rocks like the flower bed.

I will dig the turf out.

My plan is to have about 2-3 inches of sand leveled out across the dug out turf/sidewalk areas and then put the flagstones in. Since the sidewalk area will be "higher" than the area with the dug-out turf, there will likely be 3-5 inches of sand in the removed turf area.

FYI, I live in Tulsa, Okla., which is Zone 6/7, so we have basically mild winters. Maybe 1 or 2 snows per year, and we never have around-the-clock below freezing temperaturs for more than a day or two at a time. (And many times its in the 60s or 70s two or three days later.)

Questions:

* Is this realistic? I know it would be BETTER to take the sidewalk/concrete OUT, but this would increase my expenses and labor greatly.

* Do my boundries seem like they would appropriatly hold the sand bed in place?

* I'm thinking a good idea, instead of 3-5 inches of sand where the turf would be dug out would be to fill in gravel in that area, making the gravel essentially level with the sidewalk, and then put 2-3 inches of sand over the whole thing.

* Any other thoughts?

If your sidewalk has a big slope to it, you may be alright.

Sand is for setting the stones, and should be 2 inches. Do not use 3-5 inches, that leaves too much room for shifting. Use 3 inches of gravel, tamp it down, then 2 inches of sand over that.

Overall, ensure that heavy rain has someplace to drain to, to not pool in the sand.

gottagarden - the sidewalk actually does have some slope to it. It slopes down toward the left of the picture. In fact, my entire yard has a pretty decent slope moving from right to left in the photo. For example, that corner that you're seeing in the picture is the NW corner of my house. In the crawl space on that end of the house, I have to almost literally crawl on my belly, but in the crawl space on the opposite end of the house, I can almost stand up.

Hey bailey09 - the sidewalk area is maybe about 30-40 sqare feet (approx. 10' x 3'), and then the grassy area will cover say another 30-40 sqaure feet.

On the other side of the purple line is where wood steps lead up to the "upper level" of my wood deck. The sidewalk continues under the steps for a few more feet, and then "drops off" to a large concrete slab that the largest part of my deck covers. As I said above, the whole area has a pretty steep grade moving from right to left, so the whole area drains pretty well.

Here's another image to illustrate - if you look in the lower left corner of the picture (through the railing) you can see the steps leading down to the sidewalk:

The sidewalk looks in good condition so I would not take it out. I would mortar the flagstone to the top of the concrete sidewalk and then either (1)pour a 2"-3" concrete base (like a footer) in the grassy area and then lay the flagstone on top, or (2) use a 2"-3" crushed granite base and sand to level with a sprinkling of cement to hold the flagstone in place, or (3) as a last resort lay the flagstone in the grassy area and remove the grass from beneath the stone, use sand to level. I hope my options make sense.

bailey

Yes that sidewalk continues down the side of the house, but it continues for about 10-15 feet before hitting a gate that goes into the front yard.

Practically nobody uses that gate and walkway except for me when doing yard work (virtually all guests enter our back yard through the house), and I'm not sure I understand what you mean by having to "step up into the back yard."

While the flagstone wouldn't be level with the concrete obviously, I figured it would only be raised up maybe 3-4 inches when all was said and done - considering that a 2" thick flagstone would be set into a 2-3 inch bed of sand.

Am I missing something?

I sympathize with not wanting to remove the concrete, but agree that mortaring on top of it would make more sense. In effect, you're not installing one patio here but two different ones that abut and adjoin, even if some of the stones go across the divide between them. Treat the base preparation differently.

Quick question about mortoring the flagstone to the concrete:

This may be a dumb question, as I have no experience mortoring or laying concrete - but is it OK that the concrete sidewalk, as is, is not level?

As I said earlier, it has a bit of a grade to it, slanting down from right to left in the photo. Does that mean that I would just have a "deeper" layer of mortor on the left side and the flagstones would then be leveled as I lay them?

Also - for the part that would be mortored to the concrete - would I still be using sand "in between" the stones? Or would that also be mortor? I guess the reason I ask that is because it would seem to be the case on the part laid on the grassy area -- or have I confused myself? ;-)

I also don't know about the sand, sorry. Try asking at the stoneyard.

On the grassy area: You are going to remove the grass down maybe 3" and add crushed stone or granite gravel, lower than the old sidewalk and depending on the thickness of your flagstone. Now tamp it down (again leveled or slopped)and sprinkle some dry portland cement on the top. In this area you want to use a thicker flagstone and you are only going to use enough sand to level the stone. When all the stone is down mist everything so that the portland grabs onto the flagstone and the gravel. Now you are ready to grout between the stones and it will look like one continuous patio.

The only place that you will need edging is where the stone is not held in by something e.g. the edge where the steps are. I've actually used the thin edging for pavers that you get at the big box stores.

My step comment had to do with the blue line and the lag bolt trim pcs but if you mortar the flagstone you won't need anything special there.

Bailey

One more follow-up - is there a good guidline on the amount of admix to add to the mortor? I have no reference point for that... are we talking one large bottle per wheelbarrow or something similar?

Bailey