[dandyliondancer]

Hi all. Just wanted to say great forum. Have enjoyed the posts.

I just stumbled across a new way of dry laying flagstone – thought I’d see if anyone else does it like this. I was basically grumbling the other day to another contractor about how I was dreading leveling up a patio built from mammoth 4” broken flags, when he told me about a method he heard about from a friend of a friend, which involves using sand and running water to float in the flags, a little bit similar to setting them in mortar. Normally I set them in a thin bed of dry sand on a 5-6” base of compacted crusher, which involves lifting the stones to scrape out a bit of sand here, or add some more there, then check it again, make a few more adjustments, etc. etc. Not the most economical method when the stones are weighing in at 150 or 200 lbs, or whatever they are. According to my third hand account, the guy who was using this method was able to lay 850 sq ft of flag in one day. Needless to say I was somewhat skeptical, but after laying the first few stones the tried and true way, and becoming more grumpy as I went, I decided to give it a shot. At first it was a little bit of trial and error, but once I realized how it worked, it was a cakewalk. I was able to lay in the remaining 160 sq ft in about 4 hours (already chiseled to fit) with minimal effort, and now look forward to the next chance I will have to lay a broken flag patio.

I didn’t have many details to go on, but here is the basic method as I figured it. As usual, lay the flags on a bed of sand to approximately the correct height. Then run a hose with a light to moderate stream of water all around the edges of the block you are working on. This begins to turn the sand to “mud”. Then you can wiggle the blocks back and forth to make any high spots sink. With the really heavy flags, this was still not an easy task, so I found it easier to start them out a little low and then add sand to raise them up. To do this lift one side of the stone to the correct level with a spade or some other tool, and keep adding sand around the edge as you continue to flush it in with the water (it helps a lot to have at least 2 people). Like magic the sand “sucks” right in to any gaps under the stone. Nature abhors a vacuum, right? When the sand stops being sucked in, you are done with that side. I found it best to keep some leverage on the stone for about 20 seconds, to let the water drain and the sand firm up, to avoid any sinking. Then repeat on the opposite side and you are done with that stone. Move on to the next and the next, and then sit back and grab a cold cerveza.

Also, if one end of the stone is high and one end low, raise up on the low end and run water over the high end while wiggling the stone, and the sand will wash from the high end to the low end.

This method not only is quick, but completely fills any pockets under the rocks, and hardens up the sand to make for a very stable set.

In the final step I scrape out any sand in the joints and fill in stone dust.

I would be interested to hear how this compares to how other people set broken flags.

Mike

[dandyliondancer]

btw. here is a pic of part of finished project

[Stonehenge]

Tight, consistent joints and looks extremely level - very nice work. I have a great appreciation and admiration for those who sweat the details on projects like these - really pays off in the end result, IMHO.

Personally I've never tried the method you describe - we pretty much gut it out using the old method you described, complete with a massive grid of string lines to make sure we keep the pitch consistent.

One thing we do differently is using polymeric sand in the joints instead of stone dust or screenings. Even in larger joints it seems to hold up well, and it won't find it's way onto the face of the stone, and will help prevent water getting under the project, reducing the chance for freeze-thaw issues. We've used this sand on pavers for 3-4 years, but only started using it in flagging installations in the last year or so.

Nice work.

[jwholden]

Sounds like something I'll have to give a try. I couldn't install 160 square feet of random flagstone in a day!

I'm dying to try mixing portland and stonedust and use that as my setting bed on a small stone patio. It sounds like a much quicker method than laying it dry.

[dan deutekom]

I can't wait until my next random flag job to give this method a try. It also sounds like it is a much cooler way to do this work on a hot day.

[motoraced]

just so you know, "4 corners" is bad. and you have 2, 3 if your anal, already in that pic...

there are rules to flatwork, especially flagstone.

[Nebraska]

Originally posted by motoraced
just so you know, "4 corners" is bad. and you have 2, 3 if your anal, already in that pic...

there are rules to flatwork, especially flagstone.

You lost me motoraced.....can you expand on that?

[dandyliondancer]

good point, motoraced. what he's saying is that its not as aesthetically pleasing to see 4 lines comming together at a point, especially at right angles (not as "random"). just like you try to break up long seams, so they don't draw the eye too much. doesn't really have anything to do with the stability of the finished product. i think all of my four corners got into that one pic. pretty sure the rest of the project didnt have any more. i thought that the corners between the two large slabs were offset enough that they didn't really stand out too much. just my opinion. as you said, if i was more anal . . . the other corner wasnt really a corner until i hit one of the stones too hard with a mallet, making a new seam, and then didnt make the effort to find or chisel another stone to fit that exact spot. (i think thats when i started getting grumpy and decided to try the "floating in" method) sometimes i think you just have to stand back and ask if it works in the end, rules be dammed. for me and the client, it did, but i respect any opinion to the contrary, especially if it has to do with being a stickler for details.

anyhew, i never claimed to be an expert at this - the whole reason for this forum i think, and will keep my corners more in mind in the future.

ps. maybe its getting too off topic, but are there more "rules" i should know about?? we could make a list! . . .

[motoraced]

my rules for random square cut pattern it NO 4 corners, no 2 same size stones next to eachother (such as a 2 18x18 basically so no box it made up) no joint lines made up of more tha 2 stonesbut NEVER more than 3....for broken flag...this is hard to explain in type, i wont cut one stone to make the other fit...as in dont notch one stone so the others point will fit into it, cut both stones...gives it more atural look...
the thing is with these "rules" its personal preferance...this is the way i think it should be done as a craftsman, but in the end, the owner wont know the difference and you'll still get the check

[VoodooChile]

motoraced,
Sounds sound, but a picture is still worth 1000 words...

[motoraced]

i sent pictures to the admin so they could post them, but they havent.

[Stonehenge]

I haven't received anything. You may have to resend. But as a side note, I don't mind doing that once or twice, but ultimately I'd prefer that you discover how to resize your pics (we have a tutorial you can find from the main page), so I can spend time working on other aspects of the site (and my own landscaping business).

Jeff

[VoodooChile]

Steppable ground-covers like Irish moss, Creeping Thyme, some Sedums, and Ajuga, as well as standard issue moss, are a great way to cover imperfections/add character with flagstone projects.

The seating area below is composed of scraps (especially the left-hand corner), and is more a bubble in the path round my house, than a full-fledged patio. It's rustic, but useful space.

[VoodooChile]

Whoops!

[tfld]

pull it up, start over. Just kidding, an exception to the rule(s)...