by Connie Oswald Stofko
Last month, we talked about a project most home gardeners can do, building a garden wall, and we discussed the advantages of using natural stone instead of concrete. A reader asked if we would do something about building flat areas.
To recap: In the previous article, we talked about building a garden wall that’s 6 to 12 inches high. It’s a little easier using natural stone than concrete because you can skip some of the preparation steps that you have to do with concrete, said Ethan Waterman, manager of Waterman’s Greenhouse, 12317 Vaughn St. (Route 240), East Concord (Springville).
But when doing a patio or walkway, there is a lot of preparation, both for natural stone (flagstones) and concrete pavers, said Claire Brown, CNLP, president and designer at A Growing Business, 11554 Wyandale Rd., Springville.
With concrete pavers on a flat surface, you have to make sure everything is level or the imperfections will be noticeable. You don’t have to be quite as fussy with flagstones, Brown said, because flagstones aren’t perfectly smooth and flat like manufactured pavers are. Flagstones have an uneven surface, so small differences in height are expected.
Still, you have to follow all the steps in preparing the base for your patio whether you’re using flagstones or manufactured pavers. If you try to take a shortcut, your finished project won’t last as long, Brown said.
Her company, A Growing Business, would be happy to design and install a patio or walkway for you, “But if you have the wherewithal, why not do it yourself?” Brown said.
This is a project where having the right tools can help, she said, and you can rent tools.
But it’s also important to know that some of the steps in this kind of project involve lifting heavy flagstones (one flagstone could weigh 100 pounds or more) and some steps can take a long time and can get tiring. That tempts people to take shortcuts, and you don’t want to take shortcuts in this kind of project.
To see whether this is the kind of project you might want to take on yourself, let’s get an overview of what is involved.
Materials for a flagstone patio or path
The natural stone that is used for short garden walls is small and easy to work with, so some people like to use it for walkways or patios, said Waterman of Waterman’s Greenhouse.
However, there are advantages to using flagstone, he said. The flagstone is larger and one piece covers more area than a small piece of natural stone will cover. With flagstone, you’ll use fewer pieces in your project, so you’ll have fewer edges to line up and fit together. Flagstone is also more uniform in thickness.
When using flagstone, you’ll want what is called stand up flagstone irregular. It’s irregular because each stone is a different shape and size, he explained. It’s stand up because the stones are placed standing up, rather than lying down, on the pallet.
The stones on any given pallet will be within a range of thickness. The ranges are 1 ¼ to 1 ¾ inches and 1 ¾ to 2 ¼ inches. A large stone might be 3 feet by 4 feet or 4 feet by 5 feet, and smaller stones might be 2 feet by 2 feet.
Stones are sourced from different parts of the country and come in different colors. Waterman’s can get stones in other colors, but the most popular colors are:
- Full color. This is a range of brown, gray and green tones.
- Blue stone. This is blue and gray tones.
- Lilac. This includes dark red and burgundy colors.
You can also mix colors.
“Mixing them looks nice and it brings out the different colors,” Waterman said.
Each color is priced differently. If you take the dimensions of the path or patio that you want to build, the staff at Waterman’s can help you calculate how much stone you will need.
A pallet of flagstone isn’t something that is going to fit into your car, but Waterman’s delivers.
They also carry polymeric sand, which is used to fill in the joints (the spaces between the stones). The polymeric sand has an adhesive in it that makes the particles of sand stick together. Rain can pass through it, but it won’t allow weeds to grow up through it.
For more information, contact Waterman’s at 592-9186.
Building a patio or walkway
Prepare the base
Whether you’re building a patio with flagstone or manufactured pavers, the preparation is pretty much the same, said Brown from A Growing Business.
You need to prepare your site in order to prevent the ground from heaving in the winter.
“Because of the climate where we live, everything that holds water freezes,” Brown said. “When water in the ground freezes, it expands. When it thaws, it contracts. That makes the soil move up and down.”
Most of the freeze-thaw problems happen in the top 6 inches of the ground, so in that area, you want to layer materials, such as crushed stone and sand, that allow water to drain through.
Dig up the area for your patio or path
The first step is digging down about 6 or 8 inches to accomodate all your layers of crushed limestone, sand and flagstone. There will be about 5 inches of fill material, then your flagstone.
Depending on how big an area you want to for your patio or path, that could entail a lot of digging. You can rent a skidsteer or mini-excavator to help with that task.
Add crushed stone and tamp it down
After the area is dug, you’ll add about 4 inches of crusher run, which is fine crushed limestone. You could use gravel, but gravel doesn’t compact as well and the layer won’t be as solid, she said.
Depending on the size of your project, there could be a ton or more of crushed stone that you have to move from wherever it is dumped, probably your driveway, to the site of your project, such as the backyard. You might be able to use a skidsteer to help move it where you want it.
You’ll lay down an inch of crusher run, then tamp it, then lay another inch of crusher run, then tamp, and so on until all four inches of crusher run is in place. When you’re done, the crusher run will be hard, almost like concrete.
You can buy a hand tamper, which is an iron plate on the end of a handle, or rent a gas-powered tamper. The power tool is easier and does a more thorough job, she said.
When you’re using concrete pavers, you have to get the crusher run absolutely level, but that’s not as important when using natural flagstone.
If your patio or path will be up against your house, you need to pitch the crusher run so water runs away from the house. You need a pitch of between 1/8 and 1/4 inch per foot.
Add a layer of concrete sand
The next step is to add 1 inch of concrete sand on top of the crusher run. Concrete sand is different from play sand; concrete sand is coarser.
The sand will be the bedding material for your flagstone. The crusher run is hard, and the sand will allow some flexibility.
Place the flagstones
Now it’s time to place the flagstones. If your patio or path is up against the house, start at the house. Otherwise, you can start anywhere.
Start with one of the largest stones. Then choose another stone that seems to fit well with it. Maybe a curve on the second piece complements the curve on the first, or perhaps they join well on a straight edge.
You also want to choose pieces that are approximately the same height; you don’t want one piece of stone sticking up higher than another piece. If you have to, you can pick up the flagstone to remove some sand, then set the flagstone back in place. Or you could choose a different piece.
“That’s where the challenge comes in,” Brown said, “because you have to do this on all sides of every stone.”
Since you’re handling a stone that could weigh 100 pounds or more, “Here’s where it gets backbreaking,” she noted.
Work across your project area; don’t jump around.
“It’s a puzzle you put together on site,” Brown said. “You can’t map it out ahead of time.”
Tip: For the best possible outcome, always overbuy your flagstone, knowing that you won’t use it all.
“To have more to choose from will make the project easier,” Brown said.
Another tip: When buying the stone, look carefully at the stones on the pallet. Choose a pallet with stones that are flat and uniform.
You can also cut pieces to make them fit together a little more tightly. You may have two large stones that would work perfectly together, except that one has an awkward point. You could cut off that point using a gas-powered concrete saw with a 14-inch blade, which you can rent.
When you get all the big pieces laid, you will have gaps that you need to fill in with smaller stones. You may want to cut the smaller pieces to make them fit tightly into those gaps.
You could leave your patio or pathway with an irregular edge or finish it with a straight edge. If you want a straighter edge, you can cut off points or curves along the edges of your project.
Add polymeric sand
Polymeric sand, which has an adhesive in it that makes the particles of sand stick together, is used like grout to fill in the joints or gaps between stones.
The adhesive is activated when it gets wet, so it’s important to keep your whole area dry. If the sand gets stuck on top of your flagstones, it will make the surface of your stones gritty, Brown said. Read the manufacturer’s directions on the polymeric sand. Make sure to check the weather forecast.
Pour the polymeric sand over the top of your flagstones and sweep it into the joints, filling them up.
A tamping step is next, but before you tamp, put plywood across the top of the flagstones to protect them. Use the hand tamper; the power tamper could break the flagstones.
Tamping will get rid of any gaps between the bottom of the flagstones and the bedding layer of sand. It will also help the polymeric sand settle. Some of the polymeric sand may vibrate out as you tamp and you’ll have to sweep it back in.
When you’re done tamping and sweeping, you activate the polymeric sand by sprinkling it with water.
When it’s dry, you can set your patio furniture on it and enjoy.
If your project is a little higher than the surrounding lawn, you can add a bit of topsoil to bring the lawn up to grade.
Planning and design
Before you start your patio or path, Brown suggests taking some time to plan it.
Consider questions like these: How do you use your yard? How do you plan to use your patio? Will you just eat outside or grill, too? Do you need room for children or pets to play in? How does this project fit into the overall design of your landscape?
If you’d like an estimate on a design for your landscape or an estimate for installation, you can contact Brown at 592-1491 firstname.lastname@example.org.