I’m dropping by from Cooks Talk with a question about dry setting flagstone for a small patio. We are faced with some quick decisions regarding the construction of said patio.
The landscape architect, a friend, started with the idea of leveling our soil by excavating 5 ” (we are on a knoll, rocky, extremely-well-draining spot in the Napa Valley), putting in 3″ of sand and setting the stones about 3″ apart with a mix of mushroom soil and our soil, in order to plant wooly thyme between the stones. The thyme would be planted at the base level of the stones in order to grow up even rather than mounding.
When brainstorming this, she changed to just leveling, putting in just the mushroom/soil mix, watering it, rolling it, then placing the stones. When we were picking out the flagstone yesterday the salesman indicated that they should be laid in sand. Also that we would wet the sand to “set” it.
Our friend is in the mountains for a week, the laborer speaks only Spanish, and before we order the soil or sand, we’d love some input. All this has happened in a few days because our friend is attempting to keep this fellow working while she is out of town. Normally, we would be proceeding more slowly with more caution. Yikes!
edited to correct errors
Edited 9/22/2002 9:13:00 PM ET by AP on KP
Edited 9/23/2002 4:25:49 PM ET by AP on KP
Replies
Greetings. I am not a stone setter. However, all the flagstone (salvaged sandstone sidewalk pcs./parts) that I have set have been placed on a compacted "screenings" or crushed stone. The base was a cpl inches thick sometimes on dirt, sometimes on a larger stone for drainage. When on stone, I put down landscape fabric to keep the fines from settling out. Not knowing what mushroom soil is, maybe that would be a good base. If not compacted, stones may tip and rock on a softer base. That, and perhaps a mucky mess laying em.
I would like to caution on the 3" separation if these are smaller salvaged pcs. With the firm ground at the bottom of the stone (even with the greenery) there could be some uneven footing for walking, setting furniture. Large, formal slabs might offer the opportunity to step over the crack. Here's a shot of the small stone random pcs. outside our door with about a 3/4" spacing. Small enough that the legs on the chairs don't get hung up. Best of luck and I'm sure you'll get some better feedback here.
__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Thanks so much Calvin, for such a quick answer. We are going to order "patio select" Conneticut Bluestone. I am a bit worried about the wide cracks too, but wonder if a more narrow one would allow enough space for the thyme. Our landscape person/friend told us to get the flagstone pronto so the man laying would have it to finish this next week, but the company didn't have enough for us in stock. That means we have a little more time to figure out the "crack issue" I guess. Everything is moving too fast for these 2 southerners. We like to take our time. ;) I do have to order sand tomorrow though if we need it. Mushroom soil and our soil (which is like rock dust) wouldn't be too messy, but I wonder if it would be too soft. Doesn't the sand sort of "set" or "interlock" if you wet it? And friend mentioned rolling the mushroom soil, but not the sand.
One thing about this area is women rarely wear high heels and are pretty used to dealing with "rustic sufaces". I'd have to warn them to wear flat shoes I guess. This patio will be small, about 350sq. ft. just off a deck, with a lattice fence around it. We are in a wooded area and I want to be careful with the tree roots. There are 2 Japanese maples and several Black Oaks in this spot. (If the oaks don't succumb to the sudden oak death disease that is moving over our way from Sonoma County.)A book is like a garden carried in your pocket. Chinese proverb
If you're going to walk on it, you shouldn't put mushroom soil under it. (I'm assuming mushroom soil is spent compost from growing mushrooms.) The organic material will eventually rot and the base will settle, probably unevenly. As calvin described, stone dust is the traditional base. Sand will work, but it'll work better if you get graded sand, not all the same grain size, like they use in making concrete.
If you're not going to walk on it, if it's just a background for the thyme, you don't need any particular base under it.
Hi Uncle Dunc, I think I got the right sand. First crisis delt with. Thanks for your input. (I'll help you with a cooking question on CT if you need it.)
Now I hope the stone co. can come up with the color of flagstone we want. Also, I hope this fellow excavating today can deal with the heat. At least we don't have any humidity. I'm keeping a pitcher of ice water handy for him. A book is like a garden carried in your pocket. Chinese proverb
It must be scorching hot up your way... it's approaching 100 degrees on the Peninsula today, the kind of dry offshore breeze hot that wicks every vapor of moisture out of you.
I did a ct bluestone patio this summer, 24" square cut stone. It looks great, but I would do a couple of things differently next time. First, I would lay down a 3" base of crushed stone and machine compact it, then I would lay a 1" layer of sand to level the stones (they are pretty flat to begin with, but there is variation in the thickness that needs to be accounted for). I originally used a compacted sand base of about 2" thick and throughout the summer the stones settled here and there slightly, creating some wobble stones and a few ridges.
I spaced my stones about 1 1/2" apart and filled the gaps with crushed granite pea gravel, a bad idea that I will fix this winter. The gravel catches everything and blows out when I hose down the patio. I will probably push the stones tight and add another row to make up the difference, and brush granite dust into the gaps. I am interested to hear how your thyme works out, I may go with that option as I always liked that look.
Hi Jeff. Yup, it's warm up here. Tiny bit cooler today. I'm praying for fog.
Our friend/landscape architect told me that they put in a flagstone patio with pebbles between the stones and after a year, changed over to thyme because the pebbles were always escaping and were a nuisance underfoot. I hope this works for us.
PS If I am not around Breaktime, come over to Cooks Talk and snag me . I might forget to get back with news about results. I forget a lot these days.A book is like a garden carried in your pocket. Chinese proverb
First, a question...are you setting the bluestone three FEET apart, as you wrote in your initial post, or three INCHES apart, as calvin supposed in his first reply?
I'm guessing the three FEET was a typo.
First, as was already mentioned, the mushroom soil/compost is all organic. Do NOT put this under your stones, as mushroom compost is like a sponge...it swells when it gets wet, and shrinks again as it dries. And yes, the action is strong enough to heave the stones. and again, as was already mentioned, as the organics break down over the years, your stones will sink unevenly.
For the base, sand is okay, but stonedust, or granite dust is better. Have the area of the patio cleared and excavated down to remove all organics. You need to get down to subsoil. If 5" works, then that's great. If the proposed patio location is close to or abutting the house, ensure that the subsoil base also pitches away from the house (1" of drop per 4-6 feet of run) to prevent water from funneling to the house. A base of 3" of stonedust is on the shy side...but with good drainage and with a non-freezing climate, it should suffice. Spread about 3.5"-4", then compact it down to 3". Once compacted, you should be able to walk on it without leaving footprints. If you see footprints, it's not compacted well enough. Misting it before, and even after, compacting it will lock the grains together. You can manually compact it over several hours with an 8" square plate on a length of pipe (sold at home centers), or rent a plate compactor for a few hours and have a fabulously compacted base in about 10 minutes.
With regular-shaped patio select blustone, you can lay them closer than 3". I'm in CT, and here 1/2" to 3/4" is typical. And yes, that narrow gapping still works well for thyme. I lay the stone, see how it sits, then lift it and add/remove a bit of stonedust as required, then reset the stone so it sits securely.
Realize that thyme likes dry, gritty, well-draining, nutritionally deficient soils...which describes stonedust just perfectly. After setting the bluestone over the stonedust base, I fill the 3/4" gaps with more stonedust and plant the thyme right in the stonedust. A couple of times a year for the first few years I pull up a few chunks of thyme, separate them into many pieces, and replant the individual pieces in other areas of the patio.
It thrives.
If you still decide to use mushroom compost, use a very, very lean mixture. The thyme will grow in stonedust...while thyme and weeds will grow in a stonedust/mushroom compost mixture.
Also, since you're dry-setting the bluestone in stonedust or sand, use the thicker 2" (sometimes 1.5") bluestone. The thinner 1" bluestone is only for setting in a mortar base.
Thank you Mongo, for your reply. I did mean 3", which sounded pretty far apart to me, too. The mushroom soil question is solved because they didn't have any that was decomposed enough anyway to use for that. I ordered the sand. The stonedust didn't seem to be an option. At least I'm not in the position of questioning my friend's choice of material. That gets touchy. Sort of like looking a gift horse in the mouth.
I got some amended soil for the thyme, but maybe I don't need that. Our soil has absolutely no organic matter and drains too well. It's essentially pulverized rock. So maybe he can mix the two together. We have no rain at all from about April until maybe some in Fall, and then lots during the rainy season-Jan, Feb, and sometimes March.
We are ordering the 2" flagstone, patio select, full range of color. Thanks for the tip about footprints. I think the Mexican fellow she has doing this has probably done it before many times, but since we can hardly communicate, I want to make sure. My Spanish is very limited, as is his English. We laugh about it, but it makes for risky business.A book is like a garden carried in your pocket. Chinese proverb
How bout you take some photo's of the progress and even after that greenery grows and post em. This kind of thing has always been of interest to me.
gracias__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Alas, I have no digital camera. Not yet anyway. Maybe I could get my brother to come up and take pics to post. (In his spare time :)) If this turns out well, I am going to be anxious to show it off. I'm not sure how long it will take to get the fence done. Most things like that cost an arm and a leg here.A book is like a garden carried in your pocket. Chinese proverb
Regular picture and a scanner will work too. And on the fence, I'm figuring a garden fence right now and so far the arm is taken care of. If I can just keep the leg to the knee, I think the homowner will bite. Best of luck.__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Here are a few pics I had on the hard drive showing a bluestone patio in progress. Upper level is about 50' by 22'. Lower level is about 40' by 7'. Stone is full-color bluestone.
Pics aren't the greatest resolution, I Photoshopped them down to 10-20KB per pic for quick loading:
Patio2: Rough excavation, beginnings of retaining wall.
Patio3.5: Day laborer who works for food clearing the rubble.
Patio5: Subsoil base fully prepped, perimeter footing poured in place.
Patio6: Forty tons of stonedust placed one wheelbarrow load at a time. Compacted depths 5-6" on the lower, 8-9" on the upper level.
Patio7: Stonedust base compacted, perimeter bluestone coping mortared in place.
Patio8: Laying the stone.
Patio11: Stairs completed connecting upper and lower levels.
Patio12: View from the upper level.
Patio13: View from the lower level.
Edited 9/23/2002 10:59:41 PM ET by Mongo
Thanks for all the pics!! I especially like the day laborer who works for food. Tell him I am a good cook. Maybe we could work something out!A book is like a garden carried in your pocket. Chinese proverb
He'd be thrilled since the only food I'd give him after a day's labor was oatmeal...dry oatmeal at that.<g>
Oh that poor baby! He needs to unionize!A book is like a garden carried in your pocket. Chinese proverb