Pea Gravel just won’t stay between Flagstone
…or will it?
Hey everybody. This is the part of the show where stone artist Devin Devine answers mail!
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Deni writes to ask:
I have a small flagstone courtyard that when put down over 8 years ago looked like your one picture that used the small pebbles between which looked great, however over the years all the pebbles are about gone. Is there anyway without having to rip up the flagstone to put mortar between the rocks instead of pebbles for a more permanent look? My dog uses that courtyard to do her business so I am always using the hose to wash it down and would end up losing all my pebbles again. I had seen on one those home improvement shows about a product might work but can’t remember what it was. Any ideas?
Use larger river rock
1″-1.5″ river rock is what I used in the photos you saw. They are still where I put them, 3 years ago. These stones are nearly as large as the gap between the flagstones that they fill–so I had to get down and carefully put them into place, I couldn’t just sweep them in like you can do with smaller pea gravel. Neither rain nor a hose will dislodge them either so an extra hour of installation time did not bother me much.
Tools needed to build your stone patio on a gravel base:
- grabo, the hot new vacuum lifter that makes lifting flagstones a bit easier. My review can be found HERE.
- dead blow type mallet. Many types to choose from….lately I mostly use my rawhide mallet, but the rubber headed modern style .deadblow is in my tool bucket too, and I’ll use whichever is closer on hand.
- brick hammer, for cutting flagstone.
- with diamond blade. .
- Angle grinder. Same one I use. Keep this on hand for cuts that the hammer won’t successfully make, or that will take too long with the hammer
- Diamond blades.
- Brick chisel.
- A couple of 5 gallon buckets (for stone dust, when leveling stones)….shovel, wheel barrow…..4′ level
- Pick maddock. Best way to dig. Break up soil with this, then use shovel.
- Knee pads–essential.
- Hand tamper and/or plate compactor. For 100 square foot or less, I’d just use the hand tamper. Bigger than that–you might want to rent plate compactor.
Flagstone walkway with 1.5″ river rock. This provides the look of pea gravel, but the pieces of stone get kicked out of the joints less often. Need help with a hardscape project? DIY consultation services available!
On most of my jobs I sweep stone dust into the joints between the flagstones.
This is small 8th inch size chips of gravel, just a bit heavier then sand. Stone dust aka screenings/decomposed granite/grit also contains fine material, actual dust of a flour-like consistency. When dampened, it dries and hardens up a bit, and ends up staying in place. This method works great for flagstone joints from 1/4″ all the way up to 2 inches wide. If the space between your flagstones is wider than that, then stone dust may not be the best option.
Please refer to this article: sand, cement or gravel And this one too: polymeric sand versus stone dust
Sorry, there is no whiz-bang product from any hgtv or diy network that I can recommend in good conscience to do what you want it to do. There’s a lot of expensive, difficult to use products with a short life-span…and (unfortunately) a lot of landscapers use them.
Sod, moss, clover— something living, if the joints are big.
Stone dust if the joints are 2″ wide or less.
Larger river rock if you just really like that look. I hope this helps. If you appreciate my advice, you can always share my blog posts, or photos of my work, on whatever social media you use. Good luck!
Any polymeric product or acrylic product that is manufactured for the purpose of putting it between flagstones….is, in my opinion a waste. cost too much. too hard to use. Does not last. Is ugly. Oh and toxic. Natural stone, natural stone dust, natural stone landscaping. Natural.
Attention, rest of the landscaping industry: quit trying to improve upon nature. Rather, I ought to say this: quit trying to sell us plastic nonsense that mimics nature. I am here, and I shall tirelessly work to educate the savvy consumer!
Natural Stone wins. Devine Escapes prevails. Everyone wins. Cue the applause. Good night folks!
river rock in between flagstones, stone dust swept in between the river stones–very much like the suggestion made by Deni in the comments below.
Thank you so much for your quick response. Can I use a combination of the river stone and stone dust for the smaller spaces? I like your idea and sounds like something I would be able to do on my own.
I’m glad I can be helpful 🙂 And what you are describing is something I’ve done myself on a couple jobs. i placed 1″ to 1.5″ river rocks between the flagstones, then i swept in some stone dust between the river stones, to kind of lock it in place more.
When I fill the flagstone joints with just stone dust, it usually needs to be topped off once, within a year after installation. After that, the joint is usually stable enough that no more top offs should be needed. When i did the ricer rock thing and swept in stone dust around the river rocks, I noticed that a year later the stone dust had settled. I felt no need to top off though–the joints looked good and were stable. I’ve repeated this method a couple times…honestly, the stone dust may not really be needed in this case, but i use it anyway. It can’t really hurts and it might help contribute to the overall stability of the flagstone joint.
The other reason why i sweep stone dust into the joint on top off/around the river rock is this: The flagstone may have small voids beneath it. My flagstones are leveled off on a bed of stone dust….so I figure having some stone dust in the joint may be a good thing. If there is a void beneath the flagstone, or if a void forms as stone dust beneath the flagstone settles, then the stone dust in the joint should settle down into that void.
Long winded way of saying “yeah, good idea”. Again, good luck 🙂 and yes, I bet you can do this on your own.
Awesome, I can’t wait to get started on the project. It may be winter all over but here in Florida I’ll be able to work on this project this weekend. Thank you for all your input and sharing your knowledge. I can tell you love what you do and so willing to share and help others. You are blessed.
Oh now I’m smiling for real over here. Excellent. And yes, I am in fact stepping outside to shovel snow, right now. Let me know how your flagstone project turns out!
Hi Devin!
Thank you for maintaining such an excellent experience-based website with prompt responses.
We are from Cleveland, Ohio and are finishing up a combination brick paver and flagstone patio. Area was prepared with weed guard directly on top of soil with grey screening over weed guard.
1) For flagstone joints that are large, irregular and cannot be
minimized, we are going minimizing the joint gap with larger river rocks and fill with screening. Good or bad idea?
For flagstone joints that are still large after river rock placement, do you recommend to add more screening with sweeping, wetting and repeating to fill these type of joints?
2) I was hoping to get more clarification on the wetting process of
screening in between the joints. Do you find that direct or indirect spray to the joints works best?
How many times do you recommend repeating of the wetting and replacing of screen for a good solid joint that will hold over time?
Many thanks.
Jon
May is a busy time of year for a flagstone patio guy…..don’t be too quick to thank me for being responsive! What I mean to say is, sorry for the delayed response 🙂
1) I’ve done that before, placed larger river rocks within flagstone joints, and then swept screening in between the river rocks. It can look pretty neat. It can also be tricky to get the river rock in there in a way that looks good and is stable, but just do your best. Set the river rock a little bit higher then the flagstone, then gently seat them down into place with a mallet.
2) I scatter a bunch of screenings unto the flagstones. Then sweeps ’em back and forth over the jolints. Then I sweep up most of the excess into a pile and put it in a bucket or wheel barrow, get it out of the way. Then go over the whole patio with the hose, usually on a shower setting. Then let it dry a bit. When it’s mostly dry, I sweep in more screenings, into whatever flagstone joints have settled. Then hose again. When it’s dry…I sweep again! This time removing all excess. Might carefully use a leaf blower, sometimes, to remove last little bits.
It’s a back and forth thing. Some people find this part tedious. No specific technique is needed….just take your time, knowing it will take multiple passes.
Keep it up, best of luck and don’t stop being cool!
Hi Devin- Will I be able to mow over or use a snowblower over flagstone with 1.5″ river rock or mexican pebbles in between the joints? Joints will be 6″-8″.
Thank you!
The snowblower will likely pick up some gravel and send it flying along with the snow. Have you ever ran a snow blower over a gravel driveway? Cause with 8″ wide joints, you’re essentially making a gravel path, just with flagstones as stepping stones, set among the gravel. So anyway, it depends mostly on snow depth, type of blower, and how you use the blower….but likely some gravel will get tossed, at least some of the time, during some storms.
Thank you Devin. Sigh – I was afraid you’d say that.
Hi, Devin: i have a very small area to put flagstone stepping stones & rocks between about 15 ‘ L X’2’ deep on either side of a tree & four shrubs.s In AZ, where can I find smaller pieces of flagstone for the stepping stone, & rock to match the pavers in an adjacent area? Please advise. Thanks! I love your concepts, besides.
Hello,
I usually buy flagstone from stone quarries or stone masonry suppliers, but you are in Arizona. I’ve long been under the impression that decent stone, including good flagstone, was free in Arizona? New Mexico too, at least in desert regions. I understand that only about half of your state is desert so you might have a bit of a drive, but to me, nothing is cooler than finding and gathering good stone from nature.
I’d drive up to a butte, or a hillside of some sort and I’d bring a pick axe with me. Well, my tool kit would be a pick axe (or maddock) possibly a digging bar, a 3 pound sledge hammer and a brick chisel–and a large dolly/hand truck. Ask permission! If the land is owned by someone, ask permission. If the land is state park or otherwise protected, then maybe find another spot. Personally–I always “ask the place”, always inform/reassure the stones I’m collecting that “hey, it’s okay, you’re coming with me and I’ll put you somewhere good” and of course generally respect the place, leaving the site looking undisturbed.
Happy hunting and good luck with your stepping stone project!
Hello Devin, I have a flagstone patio (approx 240sq ft) with breeze (crushed granite) as the grout, some areas larger than others but roughly 1”-2 1/2” spacing. I am looking for a way to seal the breeze/ flagstone to keep the breeze from getting ALL over. The dogs track it everywhere and it seems to wash away a lot anytime I spray it down or it rains. Any suggestions would be greatly appreciated. Thank you in advance!
You don’t want to fill the joints until they are level with the top of the flagstone. Rather, you leave the joints an eighth inch or a quarter inch shy of the tops of the stones.
I’ve described my process here:
https://www.devineescapes.com/leveling-dry-laid-flagstones-how-to/
Down at the bottom of the page I describe my stone dust installation method.
I do not recommend any stabilizing material or binder for dry laid flagstone joints.
Foundations and bedding material beneath the flagstones may settle…. If your joint is made from stone dust, without any binder, then the stone dust can settle into that void…. With a binded or stabilized joint, that void will get worse, flagstones will settle…. And your binder ridden stone dust will crack up anyway.
.
I want to add a flagstone front porch area 9x 15 ft. It will be surrounded by a 24 inch pony wall. I live in Gilbert,Az.
I was led to believe pea gravel would be a perfect choice to use between stones.
With everything you mentioned perhaps brick would be a better choice. Pavers are popular in this area. Would like your opinion about using pea gravel. Thanks
Pea gravel tends to get everywhere…my recommendation is stone dust.
Hi Devin,
I’m in AZ. Any recommendation on where I can find that beautiful blue flagstone that you’re showing in the last image on this page? Perhaps what it’s called or what to look for? I’ve searched for blue flagstone and still I’m not finding anything like it. Here’s a screenshot of the picture I’m referencing. https://www.dropbox.com/s/96asp0qrsyhcpxf/Screen%20Shot%202021-11-17%20at%2010.07.30%20AM.png?dl=0
Thanks,
Dexter