Yes, I know this is off subject, but I’ve had a lot of hits around DG Patios, a post I did when I was in California. I thought I’d do a post devoted to that with a few photos.
I’ve done 100’s of decomposed granite patios and walkways in northern California and learned a few things as I went along. When I first began, the industry didn’t have a ‘hardener’ that you could add. That made for a semi-successful installation, because in the winter your walkway was mushy at best. With the advent of hardeners, the DG comes out quite nice, with minimal mush.
Get the DG pre-mixed with the hardener (some landscape outfits will deliver like this) or mix on your own in a wheelbarrow per the proportion instructions. Prepare a bed that’s about 5″ deep. Use an attractive edging. I am totally committed to Ryerson header, which is a thin hard steel that’s bendable. That’s because it disappears. It is expensive though, comes in 16′ lengths with its own stake. The other plastic headers are ugly. An alternative are the many colors and types of Trek, which is a recycled plastic material. Use the 1/2″ wide size. The advantage is that its more bendable than the steel, but it doesn’t disappear, so its part of your project design.
DG path using gold fines with low cost header
Lay down several inches of road base and use a compacter to compact it very hard and tight. Order enough DG to lay down 2″ on top, compacted. Then here’s the secret: apply the DG (with the hardener mixed in good) at the rate of 1/2″ at a time. Then compact. If you apply too thickly, the stuff won’t harden well. The DG has to be moist when putting it down, but not sloppy. Compact 1/2″ at a time till you have your desired height. Sprinkle with water.
Another method I’ve used quite successfully was told to me by the contractor at Strybing Arboretum in San Francisco. All their paths are done this way, and they get tons of traffic. For this method, DON’T use hardener. Apply a good road base foundation of several inches, maybe 3 or 4″. Then apply only 1/2″-3/4″ of compacted DG. Essentially this is a dusting. You will have to reapply every few years depending on your traffic. I used this method for a patio over 4 years ago and still have not reapplied. I think this is a superior method because you completely eliminate any winter mushiness. Even with a hardener there will be some mushiness.
Local fines used as DG
Some warnings: DO NOT try to apply a hardener after the fact. I once went to a potential job where the gardener had installed a walkway, then put the hardener in after he was done. Oh my God! What a mess. The whole thing had to be removed and redone.
Closeup of local fines and 3 Rivers Paver inserted for effect
Next warning. Do not install DG directly next to an indoor situation. DG tracks. It’s granite and granite gets on your shoes and gets in the house. You need at least a few steps (not many) before you go inside. My son’s elementary school built a new gym for millions of dollars. The landscape architect speced DG as the hardscape all around the gym. That was a disaster. All those kids tracked that DG into the new hardwood floor and ruined it! They finally installed concrete as a spacer.
Gray DG with Ryerson edging on one side and wooden PT rounds on the other
Next, the materials. Of course, every area is different. DG in the Bay Area came in gray, gold, or dirt brown. I’ve mixed them for different colors. Don’t be afraid to experiment a bit. A new rock came out on the market from a local quarry that was cheaper (DG is expensive. Last I looked it was around $80/yard!). I was able to get ‘fines’ and used that successfully with the hardener for a coral color.
Ryerson header and granite block decorative edge. Gravel and paver at left
For patios, I usually don’t like to have a visible drain, so I put the drain(s) on the outside in the shrub area. The exceptions are like the previous post with the photo of the sunken patio. Of course, I had no choice. But really, always remember your drainage.
One neat new alternative to DG is permeable concrete. Its more expensive than ordinary concrete, but it is nicer, much nicer, on the environment. Its fairly new and my understanding is that a good powerwash in the spring opens the pores and keeps it permeable.
Permeable concrete
Permeable concrete closeup
That’s pretty much it. In closing I want to say that I am only familiar with this material in California. I wouldn’t want to use it where it was constantly raining. I am also not sure how it holds up with snow, although I’d bet it would be fine as it moves with the ground.
Thanks for the great tips on using DG. I’m mid project and just learning about the stabilizer (and the fact that I laid too much down before the first compacting) Now I’m worried we’ve made a mess of it. I’ve laid down about 3 inches (not yet compacted) of both a path and a patio of gold fines without stabilizer. Is it possible to lay the last 1 inch with stabilized gold fines? Will that help keep down the mushiness in winter? I’d really like a very hard surface in the end.
Thanks so much for sharing your experience.
In your path and patio of 3″, where is your foundation of base rock? I always recommend 3-4″ of base rock underneath the DG.
The base rock is essential really and that too needs to be compacted for a hard surface. The stabilizer isn’t as essential as the compacting process is.
I’d recommend that you remove the DG you’ve put down. Since its not compacted nor stabilized, that should be easy. Just rake it with a dirt rake back into a wheelbarrow for reuse later.
You need to make sure your bed is prepared to the correct depth. You can get away with putting more base rock down and compacting it then you can with the DG. Compact the base rock an inch at a time. It goes much faster with an electric compactor which rents for cheap.
After that, redo the DG in 1/2″ layers, compacting each with the rented compactor. Its not really essential to use the stabilizer. I’m not sure where you live. The drier your weather the better. The farther from the house the patio is, the better. The more drainage you have, the better. I put in a DG patio about 15 years ago in my own yard before the stabilizers were around. It’s held up nicely, but the first few years, after hard rains in Dec. and Jan, the path left footprints. After many years that no longer happened. But again, I also didn’t compact it 1/2″ at a time.
Also, it sounds like you are over using the DG, with as much as 4″! This will make for mushiness no matter when you add stabilizer. 2″ compacted is plenty; even 1 1/2″ is enough compacted finish.
Again, depending on how rainy and your drainage in your area, I’d say 5″-6″ total, with 3-4″ being the base rock and the rest the DG.
OR, why don’t you just rake the DG all up, put down more base rock to within 3/4″ of desired ht., compact that, then put your final DG on top of that and compact it. Save what you’ve already bought in a pile somewhere to add later if necessary. This dusting WILL stay hard, guaranteed, without the stabilizer.
Leslie, thank you so much for your advice. We’re getting our wheelbarrow ready. We live in Kensington (just north of Berkeley) and have clay clay and more clay. The DG is in a fairly flat area with very slight slope away from an adjacent brick patio( that is adjacent to the house). Beyond the DG are two redwood trees and then a more significant slope to the back of the yard. The area where we put the patio and path is very compacted clay and is like concrete. I was advised (now I think ill-advised) that the compacted clay would make a good base and so base rock wasn’t necessary. I can’t believe I didn’t think about the drainage issue (I certainly won’t forget again after many wheelbarrow loads). I’m glad to hear I don’t necessarily need the stabilizer. Luckily we like working in the yard and it’s a great summer to be outside!
Hi Alice, my landscaping work is in Marin County, so I know your clay well. Yes, all my jobs are in clay and although its compacted in the summer, once its wet it just holds tons of water and doesn’t drain, as you know. If you’re not going to use the hardener, probably best to use less DG. If you link to my webpage (listed on my blog at the side as Ecoscapes.net), and go to my portfolio, there is a photo under ‘Tropical: Tiburon Flats’ of a patio under a humoungous Willow tree. Because of their extremely poor drainage (Tiburon flats used to be part of the Tiburon wetlands), I designed that patio with no hardener and less than 1″ of DG. That job still looks great 4 years later and never has been mushy in the winter.
Wow, perfect timing. We just put in a DG patio in our backyard and are having second thoughts. I’m so glad I found your site. We’ve got about 3-4 inches down with no stabilizer. We used a vibrating plate after we laid down all inches. Our concern now is that it isn’t hard enough. Walking across it is fine but our dog wants to dig into it (she thinks she’s at the beach) and if we drag furniture across it it will make huge marks. My husband wants to buy another couple inches of DG with the stabilizer mixed in and use a roller to flatten it out. Do you think this is a good idea? We live in So. Calif in Orange County and don’t get much rain. But they are predicting another El Nino…
Thanks!
Hmmm, I think your problem is not that you don’t have stabilizer, but that you tried to compact it after putting down too much at once. Really, the secret is two-fold: first the base rock is essential, several inches at least. Second, putting down little by little the DG and compacting it, damp, at each 1/2″. My guess is that putting more down over what you have will just make a mushy mess, even with the stabilizer.
The stabilizer is really not a secret weapon. It works just OK. I’ve seen many messes with the stabilizer if poorly laid. Also, putting down a few more inches would probably mess up your final grade height. When planning your patio, you need to plan your final grade FIRST. This also is essential for drainage planning as you need to plan how its sloped, drained, or however you are going to move water off the patio. Even in Southern CA!
Sorry to be a bearer of more work news, but your best bet is to pull up the DG, lay down your baserock properly, and put down either 2″ (1/2″ by 1/2″ compacted) of DG, or 1/2″ without the stabilizer at final grade.
Good luck.
I’ve been told you can use cement in lieu of hardener – seems like it could make sense, but any truth to that an if so, what do you think the mix ratio should be.
Hi Bill, I’ll get back to you on this because I did use a certain ratio once, and had very specific problems. Need to refresh my memory so I’ll talk with my contractor for the details. Check back in a few days.
I have now gotten the skimmy on the cement. We used it in a job last year as it was recommended by a local stone yard and the homeowner wanted to try it. I remembered we had a lot of problems and had to remix it a second time (Dig it all up!) using a cement mixer because the DG and the cement didn’t seem to blend together well.
Talking with the homeowner now, a year later, he says he would NOT recommend it as it makes the DG brittle.
I am not sure where you live, but there is a patented product called Terra Pave that I’ve seen used before for larger applications. It is more expensive than DG but sets up nice and hard, like a natural cement. It comes in many colors (more than DG) and I’ve seen it used in driveways and large walkways. It is a magnificent product.
Essentially its DG with pine pitch as the hardener and it must be applied by someone who knows how. The distributor will come and train landscape contractors on how to do the installation.
I have not personally used it, but I have also heard that it can have similar problems as the hardener does with mushiness over the years. I haven’t confirmed that though.
Good luck
We just had new landscaping put in our Davis Ca backyard. We have a U shaped planter garden box surrounded by DG. Our problem is that the DG has never dried out. At frist we thought it was from over watering the garden and the water wetting the path around the garden. However, the garden has been off for 11 days straight now and the DG is as wet and mushy as ever. After reading your site, might I conclude that it was improperly installed? What can we do now? Thanks for your time.
Hi Kim, I am wondering several things. First, the U-shaped planter box surrounded by DG. What is the drainage like on the planter box? It should have been installed so that it drains AWAY from the DG. Of course, there is always seepage in DG paths, etc. from surrounding plant material, so that might not be the problem.
Second, was the installation done by a licensed contractor? If so, then he/she is liable and must replace/repair whatever isn’t working up to standard.
Third, was the DG installed over 3-4″ of baserock first? If so, that would create some nice drainage. In addition, the slope needs to be correct so that the area actually DOES drain.
The DG should set up within days of installation, esp. in a hot town like Davis. Sounds to me like it wasn’t installed properly and you should take this up with your contractor.
One tip in using a contractor for future reference–always check online to see if their license is active. A contractor can give you a business card with a license number, but it might not be recent and active. There is a webpage with the State of CA that will list active licenses. Let me know how it turns out.
Hi there!
Great information you are sharing here -thank you!
I’m wondering if you have any suggestions for using DG as flooring in a covered dog run. There’s only one dog involved (maybe an occasional foster) and it won’t get high traffic use. More drainage needed maybe? Hardeners or not? I’m in San Jose.
Sounds like a good application. I’d recommend the Strybing Arboreteum method of well compacted base rock, say 4″, then just a light dusting of DG without hardener of 1/2″ to 3/4″. THey have tons of traffic, rain, etc. and their paths are mighty hard. Make sure your drainage is good. You might want to make the middle higher, sloping out on all sides, depending on your site situation.
I just got DG for the floor of a chicken coop, and they love it! . They take dust baths in it and pick grit out of it. I added food grade diatomaceous earth and dried & powdered eucalyptus leaves for mite control.
We left it loose but it’s great to read about how to make it firmer for paths etc
I had to add this here in case anyone has extra DG and also has a chicken or two.
I’m in Sonoma County.
I just finished a project where we installed 6″ of compacted DG over graded/compacted native clay soil (compacted) on a 2 acre lot that is going to used as a heavy construction equipment/material storage lot. This surface appears to be compacted rock hard but in high traffic areas there is a layer of smaller fines (powderlike) on the surface and is causing major dust control issues. Is this normal and is there any way to control/maintain it?
Also, since we haven’t yet experienced a rainy season, I’m concerned about the integrity of the DG following a continuous rain cycle, especially as it relates to the movement of heavy equipment/vehicles across the saturated DG. Do you see this being a problem or is the issue more of a muddy top surface?
Believe it or not, our civil engineer recommended this surface for our use. I appreciate any feedback. Thanks!
Hi Julie, No matter what you do with the DG, there is always a layer of smaller, powderlike fines on the surface. Remember, these are rock fines to begin with. That’s a lot of DG. It might work. I certainly have seen DG used for Driveways and large entrances. I suppose you just have to wait for the rains to see how it works, unfortunately. If its compacted enough, then it probably will. Personally, I might have used TerrePave or less DG.
My new pathway is complete mush!
Of course that has something to do with the typhoon we just had, but it also might have a lot to do with how i put it down. And now I’m wondering if I can properly compact it without taking it all off and doing it again.
Initially, I placed 2″ of gravel on filter fabric on compacted dirt, with trex board as an edge. I didn’t compact the gravel too well, to be honest, and then placed 2″ of the DG on it, compacting it with a hand made wood compacting thing. Since it’s not too heavy it requires a ton of pounding. But it had gotten pretty solid eventually. I sprayed water and let it dry and recompacted it, getting it to where it didn’t indent too much when walking on it. But then the rains came and now it’s way too soft to walk on. I haven’t gotten the paver stones yet due to their cost, and want to be able to walk on it whether or not i have pavers. Can I recompact it now while it’s all mushy? If I could get it fairly tight, I can place brick as a patio/walkway over it until i can afford stones, and that might be a while. But i don’t want it to be so soft. Is it too late? I really don’t want to pull it all off.
any advice out there?
thanks
Jordan
Hi Jordan, Doesn’t sound like you did anything wrong unless you put all the DG done and THEN compacted it, instead of little by little, compacting as you go along. DG will get soft but not mushy if done right. Also, check and make sure you drainage is good.
Wait until it is wet but not mushy, just damp. Then rent an electric compacter and try that. Good luck
Hi Leslie — Thanks for the good write ups on DG. I’ve been trying to locate a supplier for the edging you called out — Ryerson. I libe in Portland, OR and ma struggling to locate a good lucking edging. Any advice would be appreciated.
Thank you.
Hi John, Ryerson header goes by lots of different names. Its basically a steel header, about 16′ long (each piece) with special connector pieces. Mainly look for one that is very thin, about 1/8″ thick. Try Landscape supply houses. You won’t find them at Home Depot.
Hi Leslie,
Interesting to read about your DG experiences. I have a question about using DG as the top layer in a xeriscape garden; so it’s not a patio or pathway that will be walked on. I’d love to hear your thoughts. I helped a friend lay 4 yards of DG on about 500 sq.ft. of compacted soil, and I suspect it will not be stable when the rains come (We’re in San Diego). Most of the garden is quite steep, for one, and we installed a fabric on top of the soil and put the DG on top of that. No gravel and no compacting. Can we expect this DG to run down slope? Do you know of any guidelines for using DG on slopes?
On the other hand, nice blog!
That DG will be full of rivulets from the rain as its not a stable medium on a hillside at all. Don’t forget, its granite, just fines of rock. When you look at a stream, the large boulders are at the top, while the silt, the fines, are at the bottom of the river. That’s why farmland below mountains are so good; all the fines have run down. And that is exactly what you’ll get with your rains. I have used a bit larger rock mixed with the fines for a top mulch on less sloped areas. Call it 3/8″minus mixed with fines and its a good mulch in general and can match a DG patio next to it.
Thanks, that’s kind of what I suspected. I’m surprised that a basic web search on the subject doesn’t yield more informative results. I found your page while searching for DG and slopes (and it’s been mighty informative!), but I was expecting to find installation guidelines. Do you know any good DG references besides folks’ personal experiences?
By the way, I’m intrigued to do the hardening technique on some of the areas of my own landscape, thanks for the personal experience stories, David