The look of natural flagstone set in grass can be beautiful if done correctly and used in the right situation.
The turf in-between the stones softens the overall look of the path which can help distinguish it from other primary walkways. At the same time this technique can subtly connect different “points” in the landscape and direct the eye and traffic.
From a practical standpoint the stone path gives everybody a clean, solid surface to walk on in the event the grass is wet and/or soft.
The process of installing a path like this will vary slightly depending on circumstances such as the condition of the existing lawn. Or, perhaps there is no lawn to begin with and you want to achieve this look.
The following installation will show the fundamentals. If you have questions on a particular circumstance you may be dealing with, leave a “comment” and I’ll help you out.
Flagstone path stone selection
Flagstone Quality And Layout Are Important
Choose a type of flagstone that is dense and solid. Stay away from slates and other types that flake, fragment and deteriorate over time.
You want the majority of pieces to be larger in size and no less than 1.5″ thick. The idea here is that greater size and weight give stability – this is key.
Purchase and layout a good selection of flagstone so you have pieces to choose from. Notice how plywood is used to protect the paver driveway.
Flagstone path layout
Before you begin the actual site work and preparation, arrange the stones on top of the existing lawn how you would ultimately like them to look.
In this picture to the right the stones are set and ready to be installed. The homeowner requested that the space between the stones be kept close. Compare this to the first photo at the top. This is a different project where spacing was made wider. Keep in mind the spacing must be wide enough to support the living grass. Arrange the flagstones no closer than 1.5 – 2.0″ apart.
Remove existing lawn
Preparation And Installation Of Flagstone
The next step after arranging the flagstones is to prepare the base for installation.
Step one, removing the existing lawn, was fairly easy on this job. The grass happened to be recently planted sod and was not yet deeply rooted.
Working in sections, move 3 – 4 stones at a time off to the side. The sod can then be peeled back and the stones replaced to their set positions.
Realize, of course, that if you had a well established lawn, removing it would most likely involve some other strategy. Again, which tactic you use to remove the grass depends on the circumstances.
Base preparation and flagstone setting
With the flagstones now sitting on bare ground, you are ready to prepare the base on which you’ll set the stones.
Trace the outline of the stone on the ground with a pointed tool of some sort – a trowel works fine. Using a spade dig down 5 – 6″ within the outlined area.
In this excavated space install 3 – 4″ of crushed gravel. We like to use gravel no larger than 1/4″ diameter. It’s small enough to “move & level” with a trowel, compacts well and drains nicely too.
Now sometimes it gets difficult during this base preparation to preserve the narrower strips of earth between stones. The key is to preserve or replace soil in these narrow strips so they can support grass. If it becomes too difficult to preserve these narrow strips of soil and they combine with the gravel base, take care to ultimately fill these voids with as much soil as possible. For grass to survive in that narrow space, it must have a deep root system in soil.
Flagstone can be cut if necessary
A flagstone path in a lawn is meant to be informal. Although you can see line design and pattern, there is still irregular shapes in the stone. The pattern, which unifies the path, is achieved by relating the shape of each stone to one another.
Sometimes, no matter how much stone you have to pick from, you simply can’t find a good match. This is the time to create the shape yourself by cutting the stone.
In the picture above we’ve arranged the path to widen at the top of a stairway. Unable to find a stone to fit the situation, we overlapped one stone over another.
Flagstone cut and installed
Before making the cut we first mark a line on the bottom stone. This line mirrors the shape of the stone above with a 2″ space.
The cut is actually made with a diamond blade. Although diamond blades can be fitted on different types of power saws, here a 2 stroke cut-off saw was used.
After the cut is made the fresh-cut edge is “distressed” with a mason’s hammer to make it look more natural.
This last picture also shows a string-line set up. The string is set at an equal height from the “finish grade” at each end of the walk. You can check the uniformity of height and pitch of your walk by referencing this line at any point. Realize, however, that there are times when your walk’s finished height may have to follow a particular grade contour that is critical for drainage. Again, this is a particular circumstance you’ll have to identify on your site and adjust to accordingly.
The basic tools for actually setting the flagstones are a mason’s trowel and rubber mallet. The trowel lets you move and adjust the gravel base while the rubber mallet lets you tap the surface of the stones to set them firmly. As mentioned, the string line is helpful to check your walk’s height and pitch. A tape measure is used constantly. And last but not least, a bubble-level is important to check each stone. Also, by bridging the level from one stone to the next you can check the “height / pitch” relationship of one stone to the other.
March 6, 2010 at 8:11 pm
Hi – this is very helpful. you have a nice way of explaining things. my husband is going to lay flagstone path like this in our backyard. we don’t have grass there now. Don’t you need to set the stones in cement so they don’t move around when you walk on them? Won’t they be wobbly? Afterward, should we just lay sod around the stones? Thanks!
March 6, 2010 at 10:11 pm
Concrete is not necessary if you’re using large and thick enough pieces of flagstone. Most of these pieces on this project are handled by two men and even the smaller sizes are quite heavy (for one man). This is so important in “dry-set” work like this. Weight & Mass = Stability.
As I mentioned, you can use a 1/8″ crushed stone, but even a coarse sand would work. We find the crushed stone drains well and this is important. If you live in a cold climate, moisture built up under the stones will cause them to “heave” in the freeze – thaw cycle. Using a setting-base like small crushed stone, sand or similar, enables you to support the stone evenly so it doesn’t wobble when you step on it. You may find yourself lifting, re-adjusting the base material (to fit the shape of the bottom of the flagstone) and re-setting the stone a few times before getting it nice and stable.
Perhaps if the flagstone pieces you intend to use are small and thin you could use concrete to set them in. The concrete might bond with the thin flagstone and function like a thicker, heavier mass to give stability. I’ve never done it that way so it’s hard to say.
And yes, sod would then be installed around and in-between the stones. Established grass will also help to stabilize the flagstone and keep it from moving and shifting. The grass will actually grow over the flagstone edges a bit in time. Therefore, we do trim back the grass occasionally to keep the majority of each stone exposed.
Hope this helps. Let us know how things go.
Roger
May 4, 2010 at 2:39 pm
I have established grass in my front yard and would like to run a small flagstone path from my small side garage door over to my front driveway so that my golfcart won’t make tracks in the yard. Can I get away with not having to put any concrete under the stones? Also if I get thick heavy stone will they hold the weight of a golf cart. It won’t be used that much (maybe once or twice a week).
May 4, 2010 at 9:55 pm
Kevin,
The 2 most important things to create this path are the base preparation and the thickness/strength of the stone. Concrete is not necessary.
Decide on how the path should be configured. Are you thinking of a single width path that is wide enough for the entire cart, or perhaps 2 narrower paths running parallel with grass in between?
Remove the sod in the area(s) you’ve determined for the path(s). Now excavate down and remove enough earth to allow for 4″ of compacted base, plus the thickness of your flagstone. This “compacted” base could be 3/8″ crushed stone or “quarry process / binder”, which is what goes under asphalt roads and driveways. Home Depot carries material like this in bags.
Try to use thick, large pieces of flagstone. 2″ thick would be my choice, and no less than 18″ wide. The larger and heavier the stones the better they will set (and stay put). It’s important to adjust each stone so they sit level with the surrounding grade. Take time to adjust the base material under each stone to eliminate any wobble. I would fit the stones so that the “joints” from one stone to the next were minimal. They now make special joint sand for filling in this space. I’ve also used a material called “stonedust” for jointing.
On the outside edges of your path the lawn should be restored right to the stone so the grass and its root system knits and helps secure the flagstone even further.
This could be a nice, natural look that provides a solid surface for the golf cart. These stones will obviously be heavy to work with. Take it nice and easy and a helper would be great for lifting. This is the kind of job you can do in stages too.
July 7, 2010 at 5:26 pm
What is a reasonable price for a bluestone path with grass joints installed in Michigan? SQ foot cost?
Thanks.
July 8, 2010 at 9:50 pm
Ron,
I don’t know the pricing in Michigan, but here in northern NJ I would figure somewhere around $18 – $20/sf. This is assuming the process is complete in terms of base prep., good quality bluestone that’s at least 1.5″ thick, and care is taken in arranging, fitting and cutting the stone if necessary. Also, as I had mentioned, avoid using smaller pieces.
Hopefully whoever is offering to do this job for you can show you other walks they’ve done. Then you can say: “Yes, I like this walk and I would like mine to look just like this.” You might enjoy this article on “terminology and expectation” http://www.landscapeadvisor.com/terminology-doesnt-always-equal-expectation/
Take care,
Roger
July 16, 2010 at 2:41 pm
Roger,
Great article – thank you!
I’m starting from scratch and am wondering about the right steps to follow when a) I’ll be putting in a new lawn and b) I’d like to put in a flagstone path around the perimeter of the lawn. The flagstone path will also serve as a transition of sorts between the lawn and the raised beds that run the perimeter of my back yard. I’d like the joints between the flagstone to be filled with lawn, as shown in this article.
I’m wondering if this plan would make sense:
1. Excavate as necessary and backfill pathways with 3-4″ gravel
2. Place flagstone in desired configuration
3. Prep lawn area for new sod
4. Fill gaps between flagstones with soil, leaving space for sod depth
5. Lay sod in lawn
6. Cut strips/pieces of sod and place between flagstone
Are there any flaws in my logic?
Many thanks,
Judie
July 17, 2010 at 12:34 pm
Judie,
Great idea and look! Just a few comments:
To some degree your flagstone path/border will establish a permanent edge to your gardens. I would review all the plants (particularly the woody shrubs) that will be within close proximity to the border because as they grow and mature you really won’t have the flexibility of a grass border/edge that you can simply make bigger and bigger. Sure it’s OK for the shrub(s) to grow a little over the flagstone edge, but many people don’t realize the growth potential in their plants.
You can use 3/4″ gravel as a “lower base”, but leave enough room for a smaller gravel size on top to make it easier to adjust when leveling the flagstone. Or, just use the smaller gravel throughout.
Are there or will there be in-ground sprinkler heads? If they’re existing it’s not a problem – you’ll simply work around them and set your flagstone accordingly. If you’re planning to install underground sprinklers, try to integrate that during the prep work so you don’t have to disturb work you may have detailed and finished.
Make sure when you place soil between the flagstone for the grass you remove enough gravel so the grass has as much soil as possible to establish in. Between the heat retention capacity of the flagstone (from the sun) and then the fast-draining aspect from the gravel beneath, this grass needs all the help it can get.
Good luck with this. I’d love to see a picture when it’s done.
Roger
August 24, 2010 at 10:36 am
How did you move the flagstone around?
My pieces are 2″ thick 2′ x 3 1/2′ in size. I estimate they weigh about 300 lbs each.
Do you think I will have to rent a machine?
August 24, 2010 at 11:28 pm
Hi Kim,
Now that’s what I call a nice piece of flagstone!
I feel your pain. Moving these stones around is not easy. To handle the piece you describe without power equipment, I would have 2 men, a hand-truck, and a wheel barrow. If you use the hand truck realize that when you lower the handles with the stone on it, a good amount of the stone’s weight is going to be on the handle-end of the hand truck. If you use the wheel barrow, lift the stone (with 2 men) and “bridge” the 3 1/2′ length across the outer edges of the wheel barrow. Make sure the weight is evenly balanced before lifting the handles to move the stone.
The other issue with weight is when you’re setting the stone and leveling it. Inevitably you’ll have to lift it a few times to adjust the “setting bed” (i.e. 1/4 – 3/8″ crushed stone) underneath. You can simply lift the stone so it’s standing on its edge, have one person hold it upright while the other adjusts the setting bed. Then, use both people to slowly lower the stone down.
We sometimes use braided wire cables to lift and maneuver the larger pieces. For your situation you would have 2 lengths of cable – perhaps each 15′ long (maybe 1/8″ dia.). Situate the flagstone so its laying on the 2 lengths of cable running parallel to each other. With this method you need 4 people…one at each end of the 2 cables. The 4 of you will lift the stone into position using the cables. The cables will not really affect the leveling and setting of the stone. Leave the cables in place to continue lifting the stone and adjusting the base gravel until it sits the way you want it. When set, simply pull the cables out from under the stone.
Please be careful. Watch how you lift (use your legs, not your back). Hope this helps.
September 24, 2010 at 5:29 pm
Do you think a pathway for a vehicle (leading from cement pad on side of home to the roadway) with this type of pathway would be practical. It would not get used very often as I store a boat on the pad, but don.t think I would like the look of pouring concrete all the way to the road
October 2, 2010 at 9:08 pm
Ben,
We’ve actually set flagstone as a “driveable” surface. These are some of the key points if you intend to put vehicle weight on the stone.
1) Flagstone like this should be at least 3″ to 4″ thick. Yes, that would make them very heavy. 2) The base you prepare for them is critical. I would excavate 8 to 10″ down and fill to within 4″ of finished grade with 3/4″ crushed stone. If you can compact any disturbed earth and the gravel as well, this will minimize (or ideally eliminate) any “give” or settling. Any give or settling in the base will jeopardize the flagstone on top. 3) Now use a finer gravel (1/4 to 3/8″) on top of the compacted 3/4″ gravel as a “setting bed” to level and place the flagstone. Make sure the flagstone is sitting solidly on the finer gravel bedding so that vehicle weight on the flagstone is well-supported.
Alternatively you could excavate for the flagstone, compact the earth at the bottom, pour a 4″ or greater concrete slab (leave a “rough” surface”), let that set and harden, and then set the flagstone with mortar on the slab. The flagstone could then be 1 – 1 1/2″ thick.
Hope this helps, Ben.
Roger
October 14, 2010 at 8:04 pm
Roger -
First of all, great article. Very instructive.
What advise do you have for someone who is trying to achieve this look, but has not yet laid sod in the area where the path will go (it’s barren ground right now)? I’m most interested in understanding what the easiest installation would be.
Lay down gravel over the entire path area first and dig out areas between flagstones later to allow for soil and sod? Or only put gravel under only the spots where flagstone will go and avoid digging out “grout” areas later?
Thanks for any insight!
-Keith
October 14, 2010 at 9:06 pm
Hey Keith,
Since you’re going to be laying down sod, make sure you allow for the extra thickness the sod will add to the existing bare earth you have now. If you think in terms of the sod’s root system thickness, it usually adds another 1.5″ or so. That 1.5″ height above your existing bare dirt should be the finished height of your flagstone. Keep that in mind when you’re setting your flagstones.
With regard to your question about “the process,” it really depends on the space you decide you want between the stones (a.k.a. joint space). If the space is generous (say 5″ or greater) you could treat each stone separately. In this case you’d mark where each one is sitting (always lay out the stones first so you establish the pattern and spacing) and then dig out underneath each stone, install your base material (1/4 – 3/8″ gravel) and set the flagstone. Now you have the existing soil remaining between each flagstone ready for the sod strip you’ll install.
If your spacing the flagstones closer, it’s more efficient to treat the path universally and prepare the base throughout the area. Now you can set your flagstone pieces fluidly going from one to the next. As you had mentioned, when you’re done go back to the joints and “rake-out” a few inches of the gravel with a narrow tool. Fill in the void with soil and pack it in firmly. Now you’re ready for your (narrow) sod strip. I have a narrow mason’s jointing trowel (maybe 1/2 – 5/8″ wide) that’s perfect for removing the gravel from those narrow joints.
This time of year is good for this because it will be relatively easy to keep the grass strips and new sod moist. Of course that depends on where you live. If it’s hot, be diligent with watering.
I hope this helps, Keith.
Roger
November 7, 2010 at 11:31 am
Thanks Roger. I’m finally getting the ball rolling on this. One additional question if you don’t mind.
Think I can get away with 1+ inch Oklahoma flag? I live in central Texas (mild winters, firm soil). I know, it’s not quite your recommended thickness, but trying to see if it will work anyway.
Thanks again.
November 7, 2010 at 11:41 am
Sure, Keith. One inch flagstone should be fine for a “walking path”. Again, try to keep the flagstone pieces as large as possible. The size and mass will help to keep it stable and in place. The sod work that ultimately surrounds each piece will also help in the stability area.
Roger
December 21, 2010 at 10:57 pm
Great information Question -is there ever an application where you can lay the flagstone directly on the grass and have success with smaller paths say 10 to 15 feet?
Appreciate the help
December 22, 2010 at 8:28 pm
Thomas,
If you set the flagstone directly on the grass it will be protruding above the grade. This will be a tripping hazard and get in the way of the lawn mower. Also, the flagstone will not be stable and secure as it would be if “recessed” in the ground.
If you’re looking to simplify the whole process, how about just removing the grass and enough soil where each flagstone will sit so that the stone is flush with the grade? Essentially you’re omitting the “major” excavation work and gravel base. But at least the flagstone will be recessed and not a tripping hazard.
If your ground is hard and rocky, you could over-dig a bit and then use a little sand to set and level each stone.
Hope this helps.
December 28, 2010 at 11:58 pm
Makes sense Roger-Thank you for the follow up and I will take your advice and recess the stones-a wonderful new year to you!
January 10, 2011 at 1:50 pm
Hello,
Very helpful! I have a similar question to Thomas. I want to create a walkway about 10 feet long from my back steps to my patio. I already have sod growing in the area but it gets muddy in the rain – hence wanting a walkway. My problem is that I have a drip irrigation system under this area and if i have to dig down into the irrigation system and find all of the tubing the job will be much more difficult. I was hoping to just put the stones in the ground but not have to dig too far down because of the irrigation system. The irrigation system is about 2.5-3″ under the sod. Do you think if I just dig the sod out of the areas I want the stones, lay a little sand down I can get away it? I do want grass to grow between the stones so maybe I could stick some of the sod back in between the rocks? Do you see a problem with an irrigation system being underneath? Thanks!
January 10, 2011 at 7:36 pm
Hi Jennifer,
Is the area chronically wet? You mentioned it gets muddy during a rain, but I’m curious if the area drains well. Is there pitch to the grade so the water moves off the lawn? Is the soil porous so it drains, or is it dense with clay content so it doesn’t drain?
I don’t have any experience with drip irrigation in a lawn area – only planting beds. However, I am familiar with it from reading and what I know of drip irrigation in general. Make sure you “manage” the amount and frequency of the drip irrigation. Adjust the controller seasonally so the lawn is getting just enough water to keep it healthy. Does the system have a rain sensor or other sensing device so it does not water when it’s really wet or raining?
With regard to the flagstone path, I think you could get away with just digging down enough to fit the flagstone with a little sand or gravel (1/4″ to 3/8″). Again, the goal is to get the stone close to “flush” with the grade. The small gravel may be a better choice than the sand because it may handle the wet conditions better.
If the drip irrigation tubing is 2.5 to 3″ down, you should have just enough room to fit a thin layer of “setting” sand (or gravel) and the flagstone. For a simple pathway this should be fine.
You could check with the irrigation company that installed “the drip,” and ask about allowing the tubing to remain under the stone. They may suggest plugging the emitter holes in some way, or possibly replacing the perforated pipe section with a piece of “solid” pipe (not difficult). I myself would probably stop the water from the drip system directly under the stones by one of these 2 methods.
Be careful not to compress the drip irrigation tubing with your flagstone. As long as the tubing is surrounded by sand or gravel (or below that level) the tubing should be safe. You want the weight of the flagstone to be supported by the sand, gravel or earth and not the tubing.
Good luck, and I’d love to know how things turn out.
January 10, 2011 at 11:50 pm
Thank you, Roger for the great answer. I live in Southern CA so the area is only wet during the winter and we have had a lot of rain during the past couple of months. Nine months of the year it doesn’t rain so as long as I don’t overwater it, it isn’t usually muddy. However now I have patches where grass used to be and either the dog or the kids squished it away with their feet, leaving soft mud/dirt – one of the reasons I want a pathway. I agree it might be better to get those irrigation pipes plugged up but I think that might be too big a job for me. I’m afraid I might did up too much just trying to find the lines and make a big mess! The lines run vertically and I want my path to have a diagonal direction which also complicates taking out some of the lines. I will definitely let you know how it goes
Thanks again!
January 11, 2011 at 1:47 am
Roger
Once again thanks for the guidance. The paths turned out great. The key to setting the Flagstone was the base layer of sand. No getting around that step.
Backyard is incredible and the Flagstone turned out to be a work of art.
Best in the new year
January 27, 2011 at 12:04 pm
You have great information on designing and installing flagstone paths. I have a question. I have flagstone already to be installed but my yard does not have any grass. It is dirt but very level. I am not planning on having any grass. I want to use the sand as a filler between the stones. What do I need to do to prepare my ground since I don’t have any grass? Thank you
January 27, 2011 at 2:40 pm
Helen,
Since you’re not installing grass and, therefore, not having to mow, it may not be that important that the flagstones are “flush” with the ground. I still would excavate some of the earth beneath each flagstone and replace it with a base/leveling material like 1/4″ gravel. You could use sand too, but I prefer gravel because it does not hold moisture. It sounds like you plan to use sand to “joint” in between the flagstones once they’re set – that should be fine, but weeds will grow in sand. We often use “stonedust” for jointing. A stone/mason supply yard would carry that. It compacts really well, almost like cement, and weeds are less likely to grow in that. They also sell a polymeric sand used specifically for jointing. This we find works well too.
April 14, 2011 at 9:03 am
Great info! We are laying a flagstone path in soil and will be growing a lawn from seed. Should the stones be laid flush with the soil or a little higher? My husband started levelling them last night to be flush with the soil and is now thinking they should be higher to accomodate the grass once it grows.
thanks
Lorraine
April 14, 2011 at 1:06 pm
Hi Lorraine,
When we do a seed lawn with flagstone, we set the stones “flush” with the soil. This will ensure the stone does not protrude and cause a “trip hazard”. Plus, you want he wheels of the lawn mower to roll smoothly when they come upon the path.
Take care,
Roger
May 12, 2011 at 3:03 pm
Thanks for the information! I’m considering putting some portage stones in my back yard to make a path and was wondering if you could give me some insight. I have a couple of flower beds in back (raised ~3″) that the path will run between. Unfortunately, this is an area that gets washed out with heavy rains as it slopes from left (top) to right (bottom). I have neighbors on both sides, so I can’t simply install drains at the top and bottom. The path area is ~3′ wide by 25′ long and drops 1+’ in elevation from top to bottom. My current “plan” is to have a base layer of gravel (not sure what size) with a layer of sand (not sure what size) on top of it and the stones (16″x21″, 36lbs) on top of them with a few inches of space between each stone and river pebble between the stones. This way, the water carrying dirt, etc from the neighbor to my left will flow over the path without depositing the dirt in my yard and washing my dirt, pebble, etc away. Do you think this will work and do you have any recommendations for gravel/sand size and thickness or any other ideas? Thanks again!
-Scott
May 12, 2011 at 10:05 pm
Scott,
You’re on the right track. I would excavate approximately 6″ down from finish walk height. You should then have 4″ for a base of 3/4″ crushed gravel. You should lay down filter fabric on the dirt sub-base and then the 3/4″ gravel on that. This will ensure the gravel does not mix and migrate into the soil sub-base. This is especially important considering the runoff problem you’re trying to manage.
On top of the 3/4″ gravel lay down about a 1″ layer of 3/8″ crushed gravel as your “stone setting” material. I would not use sand. If “run-off” is a problem sand will not stand up to that.
The river pebbles sound nice for the joints. And now you have an entire walkway made of stone and porous gravel. This should work fine.
I’m a little concerned that you said “water carrying dirt” from the neighbor. If that water is carrying dirt and debris it may deposit some of it within your walkway. I wish there was a way for you to divert or even “filter” that dirty water before it hits your walk.
Let me just mention one other strategy that we’ve done in similar situations with walkways and “runoff”. If the runoff is really severe in heavy rains, incorporate a perforated drain pipe within the 3/4″ gravel base. There is rigid and flexible perforated pipe, and you can get it in 3″ diameter. Of course it has to be pitched, and I would wrap it in filter fabric, or they actually sell a “filter sock” that goes over the pipe. This will keep out silt and debris from entering the pipe.
If you think there’s enough water entering this walkway, the perforated pipe might be something to consider adding. You’re excavating for the 3/4″ gravel base anyway, and that’s the hard part.
June 25, 2011 at 3:11 pm
Scott,
I have existing lawn and wanted to install about 90 feet of flagstone path with grass joints. The flagstone is about 1.5 inches thick. I’m thinking the easiest way is to use a sod cutter set at about 2 inches to cut my path. Then roll up my sod. This should leave a good outline and flat surface in the soil. I would then place flagstone in position and fill around each with topsoil and seed. Any reason this is not a good plan. Any suggestion would be helpful. Thanks, Harrison
June 25, 2011 at 10:21 pm
Harrison,
No problem calling me Scott. I like the name.
The reason we use gravel underneath our flagstone paths is for drainage, which helps reduce “heaving” from the freeze/thaw cycle of winters. The finer gravel we use as our top layer also helps with drainage, but also gives us a medium for leveling and stabilizing each stone as we set them.
If you’re not concerned about overall drainage and “heaving” (if you live in a cold area), then you’re probably OK with your strategy. Perhaps you could lower the soil level under each stone just so there’s room for a layer of “setting material”. I say this because it might get frustrating setting your flagstone down and having them wobble or not be the right level/height. An inch or so of “setting material” could make the process (especially over 90′) of setting each stone that much easier. The setting material could be a coarse sand or a fine gravel.
Also, I’m not sure how good the sod is you’d be removing, but what about the idea of using it to fill in between the flagstone? If the sod is poor then it probably makes sense to use top soil and seed to restore the grass.
June 27, 2011 at 11:43 pm
Hi there,
I have some very thick and heavy flagstone’s (2-4 inches thick) that I will be installing in my front lawn space.
The path is going to be from my front step curving right to my driveway (triangular shaped) I’m not sure if the flagstone whould be better off to be flush with the driveway, or have it a little above the driveway? I think there will be a little slope needed from the grass to the driveway (left to right)
The main thing is what materials are best for this job for the foundation… I do want to do this the right way and do have a little experience.
I am not quite sure how deep to dig the foundation in order to support these heavy flagstones so they are good and level. Some of the flagstones are bigger in the middle than others. So I’ll need something in the centre that is workable to twist and turn them till they are good and sturdy. What materiel would you suggest I use. I need to know how deep to dig down in inches, how much screenage I need to tamp in first.
I will use some edging between the grass and flagstone to keep the grass out and weed barrier to keep the weeds out.
I appreciate your thoughts and help!
Thanks, Luke
June 28, 2011 at 4:26 pm
Luke,
Nice flagstone! They will make a solid walk once installed. Watch your back handling them.
It seems as though you will have no grass growing between each flagstone, and that’s fine. Evidently you’re planning on some kind of edging to separate the lawn from the walk area. So perhaps a decorative gravel used in between each stone in the path would look (and work) nicely.
In terms of the height of the flagstone I would try to keep all the elements (flagstone, decorative gravel joints and edging) close to flush with one another. Nothing should be sticking up higher than the other. Therefore the overall surface is without obstruction. It will look nice and seamless, and less likely to trip someone. Even the top of the edging should be close to level with everything next to it. Think of the edging as just a divider between elements, not a higher barrier.
If you excavate 6″ down you’re guaranteed enough room for setting even the thickest of your flagstones. I’d recommend using a small crushed gravel (e.g. 1/4″) as the base and setting material. It will drain well, compact well and is nice to work with when adjusting the setting bed for each stone’s irregularities.
Hopefully each piece of flagstone you have is big enough (in terms of area) so that it doesn’t shift or move. Thick is good, but they should be dimensionally wide and long as well. If you set the stones so they are flush with the surrounding grade, and then joint in-between with the decorative gravel, they should be pretty well stabilized in their positions.
June 28, 2011 at 10:54 pm
Hi Roger:
Thank you for making it sound so much easier!
So I will escavate 6 inches down now and for sure have some extra help lifting!
Should I put the weed barrier down first before I put 2 to 3 inches of 1/4″ small gravel down? Than put some more on top if needed and repeat that process.
I was wondering if I should leave the top layer of 1/4″ small gravel looser at the top so I can press and adjust the flagstones into it to fit properly or just make sure it’s tightly compacted thoroughly before laying?
Thanks, Luke
June 29, 2011 at 12:45 pm
Luke,
Yes, put the weed barrier at the bottom and then the gravel. We compact the earth (sub-base) after we excavate because that earth has been loosened. Then place your weed barrier, etc.
Compaction is important so I would go ahead and compact the gravel as you go. Since the gravel is fine (1/4″), the top should loosen relatively easily with a trowel as you set each stone. If you find it’s easier, compact the first base layer of gravel (2″ or so) and then add the “setting” layer on top of that to work with.
I’m not sure what you’re using to compact, but even a hand tamper would do the job for a walkway like this.
June 29, 2011 at 1:35 pm
Hi Roger:
I will probably use a gas powered plate tamper and a hand held tamper for the edges. I’m just not sure what type of edging material I should use for the side of the path that will be facing the grass. The other side will be pretty flush with the driveway.
I really do appreciate your experties.
Luke
June 29, 2011 at 8:52 pm
Hi Luke,
In your particular application you’ll want an edging product that will keep the gravel in-between the flagstone joints separated from the grass. As I mentioned in a previous comment, the top of the edging should not stick up higher than the flagstone and grass. Keep all elements level with one another.
I would use a flexible aluminum edging product like from Permaloc. You can adjust the height when you’re installing it to follow the top flagstone level. They manufacture several types of landscape edgings. You should probably locate a supplier near your area (use their website to help find one) and then visit the supplier to see the various choices.
Aluminum might cost a bit more than plastic, but it has it’s obvious advantages in terms of quality and durability. You might find that if you live in a cold climate the edging may “heave” a little from the freeze/thaw of winter. It’s fairly common and Permaloc has these nice long support stakes that help minimize that. If the edging does rise a bit (heave) from the winter, just use a scrap piece of wood and a hammer (or maul) to knock it back down.
Good luck with your project!
July 10, 2011 at 12:55 pm
Just as a follow up. I used a sod cutter for my path and it worked great. It cut 2.5 inches of dirt under the grass and I was left with flat solid surface to work with.
Thanks Harrison
August 11, 2011 at 10:31 am
I want to lay flagstone at the side of my house as a pathway to the backyard.
How do I handle any grading issues as I still want the water to drain away from my house. If I install the flagstone on a slight angle instead of completely level would it make the layout look off?
I would rather fill it with limestone screening or some sort of gravel because I do not want any weeds growing. I do not want to use sand as I do not want to have an any colony either.
Are there any other alternatives to fill the flagstone with to prevent weeds.
cheers
August 13, 2011 at 10:32 pm
Peter,
Your flagstone walkway should have a slight pitch to it (away from the house). If you pitch the stones between 1/8 to 1/4″ per foot it should be unnoticeable to people. So if your walkway was 3′ wide and you pitched it 1/8″ per foot, it would be 3/8″ lower on the one side. That’s what I would shoot for in a normal situation. If you feel the situation needs quicker drainage characteristics pitch the walk 1/4″ per foot. So the 3′ wide walk would then be 3/4″ lower on the one side.
As far as the joints go you could use a small decorative gravel (3/8″ or so). Depending on conditions in your area it could happen that over time the gravel accumulates organic debris and then becomes a medium for weed growth. If the joints between your flagstone are not greater than 4″ you could also use a polymeric product like Gator Dust from Alliance. This addresses your concern about weeds and insects too.
August 17, 2011 at 9:42 am
I have an area in the backyard of my rental property that currently has large “egg” gravel in it. The previous tenants dug an area out of the grass, poured in the gravel and installed a firepit. I would like to improve the appearance by laying flagstone over the gravel and spreading grass seed in between.Can I just spread some fill dirt over the existing gravel.
August 17, 2011 at 10:41 am
Alisha,
To add soil over gravel for lawn there are a couple of things to consider. First, there needs to be enough soil depth to sustain a lawn and its root system. I would say 6″ minimum. Realize that the gravel beneath accelerates the draining of the upper layer of soil, and that could cause the lawn to dry out quicker. If it’s possible, try and remove as much of the gravel as you can.
Secondly, be conscious of the finish height or grade of the new lawn area you’re creating. Keep referencing that height where you intend to convert to grass so you know how much gravel you need to remove to get that 6″ minimum.
The issue with setting flagstone over the “egg” gravel is this. I’m going to presume the “egg” gravel is large (perhaps 3/4″ or larger). I would lower the “egg” gravel far enough down so you can replace and add a layer of finer, crushed gravel (1/2 – 3/8″), perhaps 2″ or so thick. This will give you a nice “setting bed” of workable material to set and level your flagstone. The bigger gravel beneath will not be an issue.
September 28, 2011 at 5:08 pm
Hi Roger,
At the local building supply places, flagstone quantities are typically sold based on coverage per ton such as 100 sf/ton of material. I was told that this is based on pretty tight spacing in the order of 1″ to 2″. Is there a way to convert flagstone quantity calculations from “patio spacing” where flagstone are typically set pretty close together to larger spacing (say 4″ +/-) to allow for ground cover such as sod or thyme to grow inbetween?
Thanks!
Holger
September 28, 2011 at 6:13 pm
Holger,
If you’re figuring approximately 100sf/ton of flagstone, that flagstone should be around 1.5″ thick, which is good for dry-set work. If it were 1″ thick you could get as much as 160sf/ton, but I’d try to use the former.
To answer your question let me first say that in working with a natural product like flagstone you should appreciate the variability in the material and realize “your sf results may vary”. Having said that, the 100sf estimate for 1.5″ thick stone is allowing for some waste (e.g. cutting, bad pieces).
I did some quick math in terms of increasing your spacing from approx. 1″ to 4″ and realized an increase in coverage of approximately 20%. Therefore, you could calculate a coverage factor of 120sf/ton with 4″ spacing. Of course if you were doing a large “area,” say a 20 X 20′ area where the majority of the stone pieces were having 4″ spacing all around them, you might get even more coverage/ton.
Suggestion: Could you start with a conservative estimate and order more if you needed it? Or pick up one ton or 1/2 ton and see what kind of coverage you actually get before ordering the full amount?
Hope this helps!
September 28, 2011 at 6:27 pm
Thanks Roger, this helps tremendously! Using your suggestion, I need approximately 2 tons +/- and as I plan on picking the stone up myself in several trips with my truck, I’ll probably follow your advice and see how far one or one and a half tons will get me before buying too much.
Cheers!
Holger
December 15, 2011 at 12:29 pm
I’m in Houston with an established St. Augustine yard. Can I simply lay the stone on the existing grass?
December 16, 2011 at 1:57 pm
Curt,
Normally I would not recommend setting flagstone on top of grass. This does not make for a stable base. The organic make-up of the grass and roots is soft and ever-changing as the two decompose.
As a compromise you could just remove the grass and roots, and set the flagstone on the bare earth. The bare soil would at least give a more stable setting.