The house is in Los Angeles, California. When selecting your base rock, make sure to pick rough gravel that is large enough to allow the pointy edges to interlock and heavy enough not to be washed away in a storm. Most anything youd want to plant in between flagstones will grow in a 50/50 soil/stone dust mix. Last year, I installed the landscape fieldstone for a courtyard but after an injury, had to stop before completing. I want to use decomposed granite or a similar natural product, other than sand, that is tan in color instead of grey. Any idea where we could look for some advice? DG will work the same. Then allow it to dry for another 24 hours. Thanks, Mike. Low void content, contains fines, is used as road foundations. Be sure to hose off and dont let muriatic acid sit long, as it can deteriorate the joint materialmuriatic acid eats cement. I appreciate your guidance. I used stone dust under as a base and then screened gravel (sand). Just sweep the decomposed granite into the cracks between the stones, then turn on the shower to set the DG/stone dust into place. Then the top inch or 2 with the stone dust. Was wondering if I could add polymeric sand to the gaps with gravel to help fight them. Spot on! My process is described in this article: how to fill flagstone joints. Hello, could you please post a few close up pictures of the stone screenings that you use so we can try to match our locally available products as closely as possible. It is good to know that pros have to take it stone-by-stone and be patient. We have to install the permeable pavers because it was required by the city. Their concrete was too wet and/or they overworked it, troweled it too much and brought too much water to the surface. But I will make sure to get the screenings that include the eighth inch particles as well. Should I just wait until it dries out? Clay base, with about 4 of 1/4 clear gravel, followed by 1 of screening before putting down 20 X 20 patio slabs with next to nothing for gaps. Larger than half an inch= more likely to crack. But, you came to me with a need and Id rather give you a complete answer. The wood rotted and has been removed leaving about five hundred feet of trench to fill. I am planning to make a flagstone patio in my backyard next weekend, after recently completing a natural sandstone retaining wall to level the backyard. The gravel in some places is as much as 4" thick, so removing it is really the last thing I want to do. They're sold as soil stabilizers (type that into google and settle in), but the principle is the same. With large gaps like that, this is the best that can be doneis find a way to get the slope corrected. Removing the grout is going to be a horrendous job. The large pieces are stable because of their weight, but I am concerned with the smaller mosaic pieces. It consists of 3/4 gravel mixed with the same screenings that I was speaking of in the article. Its 3/8 in size, and says with finesthats what you need. A professional, who will talk with you on the phone, and walk you through the process of laying flagstone, repairing flagstone, or any other such situation? Step 1. But whatever the foundation is, it shouldnt develop such a vast chasm. Then gently give it a few taps with a mallet to seat it into place. Sorry, I was out of town and away from my computer when you posted this question. Theres also some mention of stabilized decomposed granite. Deep bow of thanks for all of the wisdom youve shared here with your article and the comment section. Life happens. And reallymaybe make the drainage saw-cut, then fill in a couple inches with road base type gravel. The red, being more rare, is sometimes available in bagged form, in garden centers, but not in bulk at the mason supply places or quarries (where I usually get my screenings, because as a contractor, Im usually buying at least a yard.). have never once needed to replace a stone, and its maybe 800 sq ft flagstone, all told. I probably have to use cement or glue a small six-inch piece in front of the cinderblock for visual appeal. Pleas re-read the above article, for my thoughts on that! You simply sweep the material into the flagstone (or other paver) joints, lightly hose down, then it solidifies. Jobsite Saw PRO has a wider table, a new dust-control port, and a more versatile fence, along with the same reliable safety mechanism included in all SawStop tablesaws. I have been extremely happy with it -- it looks great and has stayed neat, clean, and stable for two years now. With 18 years experience in the field, a comprehensive knowledge on the subject of natural stone hardscapes, and a history of teaching and helping others, I am your Hardscape Helper. Were actually fixing a poorly done patio for a friend. Finished with polymeric sand. Some joints are huge with tiny stones sort of floating in concrete. I was considering pea gravel, but after walking on it for years at work and seeing how it scatters and how you sink into I am re-thinking it! Id make the stones fit well first (assuming that the polymeric sand users left big gaps like they usually do), with a half inch (or so) gap between the stones. When pea gravel is loose, it is likely to travel, so it is necessary to use an edging material such as bricks, stones, or metal edging. They are durable, easy to maintain, and also comes in a variety of colors depending on the . The patio comes off the basement door and is surround on three sides by 4-5 retaining walls, and had a 4 drain in the pave patioit was sinking especially around the drain. Privacy Policy. Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features. Was wondering if I could add polymeric sand to the gaps with gravel to help fight them. The industry standard for flagstone installation these days, is still basically to use the methods, tools and materials used in concrete paver installation and adapt them to natural flagstone. You could do it either way, especially since you said these are stepping stonesfor stepping stones, i usually just use soil. The original plan to use the polymeric sand to seal the joints is long jettisoned after reading your blog here and others how it destroys the shine and luster of the native rock. 2. Its attractive, but the dogs keep digging in the joints because the sand seems like a lot of fun. My customer wanted no transition between the pool and the patio..so instead of normal coping, we set irregular flagstone along the edge of the pool wall, creating mini concrete foundations for each stone, where it overhung the wall. I have 4 large, thick stones for the 4 corners and many med-large stones interspersed for stability. I plan to move every stone out to the opposite side and keep the pattern intact. This is basically putting an acrylic binder, liquid plastic, on top of the joints. We surrounded the design with the rest of the flagstones in a circle (resulting in a centre medallion type of look) and then they are laid randomly to the outer edge of the patio in a normal fashion. The mix is not a slurry and is very hard to tell from damp gravel. Or, just fill the gap with road base gravel. The tile company probably makes a rubber underlayment that youll want to lay on top of the 1/4 minus. Essentially. I researched the heck out of polymeric sand, and tested out three different kinds. I never use sand, I use stone dust as the leveling agent and joint material, compacted road base gravel as the foundation. Im glad I read this and plan to steer well clear of polymeric sand. To first install the pea gravel, mark the area where the gravel will go and work the soil to a depth of approximately 5 to 6 inches. The, after laying the flagstone you re-plant the sod between the stones. The two terms are often used interchangeably, but the two products should not be used interchangeably. Or let it happen on its own. And here is how I repair mortared joints. I selected Galleries and then Flagstone Walkways, the last two images once magnified to 500% show clear images of your stone screenings. Do you have pea gravel? On occasions when I have wanted red for in-between the flagstones, Ive just used grey for leveling, and purchased a smaller amount of the red. Polymeric sand makes people think that they can cheat, that they can get away with wider joints than they would otherwise. You can also sprinkle cement over gravel to reduce sliding and shifting. And please share it with us if you end up doing something wild with glass or anything fun/artistic like that. At 1200 square feet youre going to need a triaxle load of gravel.give or take, depending on the required depth. We suspected that the sand had to be replace or refill/reapply, we just didnt know what was causing what we were seeing. Weed and ant proof. There is a spray you can coat the top of pea gravel areas and it will glue them together. This falls under the no cement at all in a dry laid patio rule. Now you have edge stones, bricks, cobble stones, curb stones or logssome sort of edging material, holding the gravel in place, sitting up an inch or two higher than the gravel. Fact is that you simply can not use polymeric sand as a replacement for taking your time and doing the job right. We didn't try to stabilize it, but what we did do is to put down flagstones in the pathways. One of the beautiful things about dry laid patios is that the foundation can withstand freeze and thaw without cracking like concrete will. I addressed the issue of weeds and dry laid flagstone here As it states in the article, personally, weeds between flagstones dont bother me all that muchand if the weeds really are that bad, then a bit of boiling water will dispatch with them nicely. Repair the flagstone. I have a slope in my backyard for about 15 to 20 degrees. The stones have large gaps between them and weeds are taking over. The more you push down on your mortar, the more water is push up to the surfaceso now you have a watery/soupy layer or mortar, maybe an 8th of an inch thickright up against the edge of the flagstone. The sales guy who sold the glue mess to the general contractor (yes, I subbed, once upon a time!) also can i just use decomposed granite to level and build the basketball court? As such the larger gap is probably his way of making them fit nicelyone big aesthetic concern is even spaced joints. If you live somewhere with winters, then it will crack up faster. The only times that Ive seen people having trouble keeping stone dust/decomposed granite in their flagstone joints, the flagstone joints were too wide. Sigh! No maintenance issues there. This will lead to headaches. To lay your flagstone patio 1) set out yours tones like a puzzle, as you said. I am considering taking the sand out, re-leveling, and filling the joints with screening instead. A metal edging or pt lumber border will look better than a plastic border.stone can be used. Were using paving sand as the base. Lots sell stone dust which is grey. Just finished laying a patio of large natural stone2-4 thick in a shaded area. Fill joints with screening. Hi I wish I could afford to hire you! I never thought about the problems I would encounter using small stones on a dry-laid patio. Shoot me an email if you think youll need personal guidance, otherwise goodluck and I hope Ive been helpful . Like on your clothes or something. Mix up type S mortar mixpre-mixed stuff is fine. Install another 46 tons of gravel, this time the appropriate 3/4 minus, angular crushed stone with fines. Also, very impressive stone sculptures! Thats kind of the main thesis of this article: do not use that stuff. Or small pebbles..but the thing is, that small voids may likely form beneath some of your patio stones. Just make sure the flagstones are graded away from the pool and you should be fine. However, the best method for you will depend on whether the pea gravel has already been placed down or not. (stabilizing the bed to lay on?) As such, it handles the Pennsylvania free-thaw rather well. Other solutions, please? We have an existing flagstone patio which was built on a layer of crushed limestone with the same in between the flagstones. Because the attractiveness of the pea-gravel surface is lessened by epoxy resin or polyurethane coatings, we found the best method was (1) above. But after reading your postings I am not sure what to do. All the flagstones should be lifted up, the sand replaced with screenings. Where can I buy stone dust? If the foundation is dry laid, repair using dry laid methods/if the foundation is cement based, repair with cementious materials. In your case, decomposed granite joints. Joints are all tight at and average of about 1/2 to 3/4 inch in width. I want to re-fill the joints of my existing dry laid bluestone patio. It does shift when the dogs play or work here. Help! Yes, concrete can be poured on pea gravel, but it is important to make sure that the gravel is properly prepared. Then I would like to avoid more polymeric sand, and use what you have described instead. Leave the joints about a 1/8 1/4 shy of the tops of the flagstones when youre finished. Im so glad I found your webpage. It does dissolve some plastics, not all, so who knows? Should be fine. I wish everyone would do that. Remove pea gravel and start over. I plan to do a flagstone patio. The gaps range from 1/4 1 between stones. It looks pretty cool as well. look at Landscaping Projects 2007, Favourite ROSES We Grow albums. Others, with a concrete border. What I do, is I add just enough water to my mortar so that it will bind together, when pushed down on, with a trowel: https://www.devineescapes.com/flagstone-walkway-re-pointing-repair-paoli/. Stapables.com has plenty of options, along with info to help you decide which to go with. Gravel is much less vulnerable to damage from seasonal . Great article Devin. Do you think installing a border on the sides of the trench is necessary? A gap much wider than half an inch will become a minor puddle spotand that water will go down into the ground. Thx, I do phone/email consultations for $93 an hour. Lets examine these advantages one at a time: Related content: One on one help is available. Kern in his book, "The Owner Built Home" talks about no-fines concrete. If stone chips are getting all over the surface of your flagstone, then the joints are probably over filled. I dissuade all of my clients from using polymeric sand. The base is stone dust, by the way, not sand. Have you ever used limestone stone dust for flag patios, and if so, would you recommend it? OR, maybe fit small pieces of stone in, laid upright/on edge. They didnt just turn to slosh. This second method doesnt clean up quite as easily as the powdery-dry method. Also, I lived in the Poconos for more than 20 years and at one time not far from your town. Check it againrepeat until its wobble-free. Or how to deal with it? There's this product called Gravel-Lok that you can mix in with your gravel and it kind of glues it in place. Beyond that, if you want to email me photos and receive personal guidance, Id be happy to help you. Using your own native soils though, a person COULD screen there topsoil and collect all gravels of certain sized, and mix them with finer sand and clay particles, and thereby create a decent soil foundation, using just what you have. 8-12 of compacted 21AA limestone (well compacted), decomposed granite and then filled the joints with decomposed granite. It does not get dug out by ants, weeds cant grow through it and it does not wash out. Check the weather, you will need two days of sun and dry weather. Do we need to remove all the flagstones, then scrape everything and start back? I am filling 1/2 3/4 joints in flagstone. (Note: I am not a professional, but love to DYI landscape). One web site even suggests a 1/3 dry portland cement/breeze mix, to then be gently soaked with water that would harden up. I cant find any advice on-line about how to apply the stone dust. The thing is.I dont think sealing the joints would really help much. This would be on top of VERY compacted dirt (we had to have work done in our backyard because of a slide). Not that it would prove anything conclusively, you just got me curious. | Paver Base Panel vs. Gravel For Patio Base | Patio Ideas On A Budget. 2" joints may be too big for polymeric (read the bag/box). Thanks again for the great advice! I then will use the 1/8 to 1/4 between the joints as advised. Ive always seen travertine fit snug with no joint, no joint material.or, with some sort of product that I dont use. (even non-shrinking exterior grout). It appears that they ripped 2x 6 in half so that they had 1.5x 2-3/4 material. Otherwise it will crack up. You have the right idea about creating a good wholesome and fun place to be with family and friends. What do you suggest using in the joints of a Limestone walkway (in NY)? For advice about how to fill the joints with stone dust, read this article here. I realize it would be better to remove everything but Im not up to doing that. Any suggestions to avoid this? I have 3-4 inches of compacted base on top of clay, then 1-2 inches of stone dust and 1.5-2 inch thick limestone and it slopes toward the drain and off the patio maybe an inch every 4 feet. Wanted to check with you the cheapest way to do it under 2K if possible? Dear Devin, Great thread. I understand that stabilized granite actually predates polymeric sand and that there is such thing as stabilized decomposed granite made with *psyllium husks, but that the term stabilized decomposed granite can refer to DG stabilized with various binders. Please share any ideas. Polymers for Sand, Gravel, Aggregate and Concrete Processing - thickeners, sand processing, dredging, dewatering, clarification , dry processes. I dont want to discourage you, and I totally think you can do this. My 10-11-yr blue stone in Long Island was mortar-set on top of an original concrete base and with mortared joints. Or falling matter from nearby trees can help cause that. Wow thanks for those great articles! I am a contractor working on a large home renovation project in Northern California. These will be an acrylic polymer epoxy resign stuff.essentially, liquid plastic. Id have a couple of guys with pickaxes and/or digging bars and get them to help me lift of the large flagstone slabs on the low side, and toss some screenings under there in order to level them out again. A soupy mortar is a weak mortar. Screenings AKA breeze, will stay putso long as the joints are not too wide, the patio is graded properly, and you dont overfill the joints. Im hoping you might recommend something. Allowing the pea gravel to dry at least 24 hours between each coat. Sorry for the delayed responseIve been busy finishing up with the years work before the winter sets in. Id prefer to NOT use itbut, i also dont want my son dragging infinesin his shoes and adding more character to our inside floors.So, if i go Screenings insteadplease let me know if you feel this is a good materials plan: 225sq.ft @ 4 fines/3/4 gravel base= 5.5 tons of fines/gravel base (Then, if i have stones from 3/4 2 thick variancehow much do you recommend in screenings for 225 sq.ft?I appreciate all your insight and feedback. Another optionfit the stones so tight together so that theres really no need for filler. If the pea gravel is used on a walkway or driveway, it can be enough to merely compress it to create stability. I might get a bag and experiment with a small section, maybe at the start of the driveway. Will stone dust/decomposed granite work in both/either area? Would prefer to be able to pressure wash is once in a while, so does stone dust make it impossible to pressure wash them? Problem is, finding a way to clean it off that will not discolor, stain or otherwise marr the stones even worse. I already clear out a 15 X 15 for my back patio. But Ive seen em fail down south, and out south west, too. A gap that small can be left open. Then tamp. We had a pro lay a flagstone floor. So fun, so tiring!). If a project interests me I can be convinced to travel. Some pieces are 2 thick x 12 long by 4 widesome are 3/4 to 1 thick 1010 size, with only a handful ideal size pieces to keep it anchored together, i suppose. IMO this is a bad idea. Once all the stones are laid, sweep more screenings into the joints. Voles, moles, or mice were causing the damage. Keep the joint material just shy of the tops of your stones, an eighth inch or quarter inch lowdo this, and your problem will be solved. Calcium chloride or other salt substitute should be fine, but salt will deteriorate mortar. In your opinion, should I use poly sand instead of DG or possibly just pour concrete? But when I see this happening on other jobs, its always one of two issues, or both: 1. Just say no to polymeric jointing sand. You also have to be very careful that the joint is filled all the way, and also make sure that there is no material left on top of the paving units, before you hose down. Make sure the patio is pitched hard enough. Lay an inch of 1/4 minus (stone dust, oathway fines, DG) over this, screed out nice and level, hose down ( on the shower setting, dont soak) then tamp. Shove some stuff under there. The stuff I used came in 5 gallon buckets. 2023 The Taunton Press, Inc. All rights reserved. Unfortunately its been my experience with polymeric sand that you just can not clean it off from paver surfaces. But on a dirt foundation, to set flagstones in a bed of cement based mortar, just doesnt make sense, for use with flagstone. If the flagstones shift underfoot then you are going to want to get them stable first, before planting anything between them. Or grind out the entire joint between the flagstones. Devin, Thank you for this blog and great info. Personally, my preference is to merely lay larger stone along the edge of the patiohave all of your edge flagstones, large. This is in New Jersey by the way. What did I do wrong? Polymeric sand is basically sand mixed with an acrylic binder. these fines, when dampened, actually do bind up with the larger chips, becoming semi-solid. Had a similar problem when we bought our current property. And the answer is alwaysmake them flagstones fit tighter! I prefer to keep them tighter, but 2 is doable. Finally, polymeric sand is an acrylic product. Are you trying to get a close match for the new mortar, color-wise? This is ideal for new pea gravel installation. No one seems to be recommending DG or granite sand until you. Surrounded by retaining wallsso the patio is below grade, and a drain of some type is necessary. Screenings are heavier than regular sand, thus theywill not wash out quite so easily. 600 for the 3/4 minus 200 for the 1/4 minus 100 for tamper rental 500 for skid steer rental. Back and forthsweep in, hose down, leaf blower, I recommend that you check out this article as well: patio maintenance. If you just have sand in.and no road base gravelthen absolutely, take up the flagstone and do it all over. So you found out about the ants! Ive seen people do this where the joints were significantly larger than the size which you described as acceptable. thanks, Chris (Santa Cruz Ca). If you wish to pressure wash a patio that has screenings for the joints, then you will have to sweep the material back into place after pressure washing. Have you seen this water proofing used before to settle the quarry dust? If theres a concrete foundation, then sure. Well, its fairly easy, but you have to becarefulthe sand is mixed with a binder. Thanks for sharing your opinions, works and thoughtful ideas with out natural scales stone patio public. There is no cement now. As easy to install as regular sand, almost. It is a mixture of Portland or other cements, water and aggregates: sand, gravel, or crushed stone. This is a big project that you are describing.. Id recommend that you spend some time reading my other DIY flagstone articles. This site is protected by reCAPTCHA and the Google. Free Store Pickup Today. Sorry! Thanks again! To keep pea gravel from rolling and shifting, tamp it down with a heavy lawn roller or hand tamper after you install it. (a careful pass with the pressure washer shouldnt damage the stones. The look is great, however, it is too soft for their liking. Shady area you say? A bit of a philosophical question, really. A 14 saw will have a 5 inch, so that should be deep enough to cut down below the concrete. You will have to reapply at some point. It was inspiring, insightful, knowledgeable and overall great advice. I remember reading about psyllium husks being used as a stabilizer, back in like 2009 or 2010, so major omission, I suppose, that I still havent studied the material hands-on. Thanks! I used the natural dirt to lay and level and pressed the flagstone cracks with the same. Its kind of silly but often people have screenings/breeze/DG all over their flagstones for the simple reason that they insisted on filling the joints in between the stones all the way to the tippy top. I wouldnt use sand, as its more likely to settle or wash away. Anyway, I would like some advice on how you achieve such tight joints. Stones will stay in place if done correctly. I am planning to level the ground and place landscaping cloth below crushing and lay stone tiles. I hope that helps. I have raw edged slate from a slate fall in the woods, so its a puzzle to fit, but super relaxing and good exercise. Google patio floor drain choose a decent looking one, read their instructions.Im available for consultations if you wish for individualized guidance on this project. Its looks like a flat matte color where there was poly sand and where no poly sand you see a beautiful high gloss high color finish.this is the best analogy I can think of. I used baking soda on my patio to kill weeds. I never recommend sealing flagstone. It is also nice to know you are willing to travel if I have a job in the future that meets your criteria!