Flagstones are those broad, flat stones you see in most outdoor paths and patios. Usually, they’re very organic looking, with irregular edges and a wide range of earth hues, from deep greens to dusty reds. But, what are these stones actually made of, and how can you use them to create your own picture-perfect outdoor features? We’ve got the lowdown on all things flagstone below.
Flagstone is both a generic term for any flat, wide paving stone, as well as the name of a specific kind of sedimentary rock that splits into thin layers. These sedimentary rocks are created by layers of, well, sediment, that are compressed by heat and pressure over a long period of time, often times underwater. Because of this, flagstones can contain pieces of clay and sand in addition to feldspar, quartz, iron oxide, and other trace minerals. Flagstones usually come in shades of red, blue, black, gray, and can often contain multiple hues in a single piece.
Flagstones don’t have to just be made out of, well, flagstone. Broad, flat pieces of slate and limestone can also be used as flagstone pavers. However, while the latter comes in lighter tan hues, it has a lot of disadvantages for outdoor use. Limestone is a very soft material that is very susceptible to water damage, degradation, and etching from acids, as well as staining and breakage. Unless you live in an area with little rain and a moderate or warm climate, limestone is probably not the right flagstone paver for your yard. It’s better to use actual flagstone or large pieces of slate, which are both highly resistant to water damage and can withstand high traffic and temperature variation without breaking or wearing away. In addition, flagstone and slate tend to age well over time, forming a kind of “patina”. Some people even like to encourage their flagstone to grow moss, to create that perfect “lost in the woods” look for their home.
Flagstone pavers are usually between 1/2”-1” thick, though they can be even thicker. Thinner pieces aren’t really recommended for use in pathways and patios, as they are more easily prone to breakage and will likely not be able to stand up to heavy traffic.
Laying a flagstone path or patio is really easy and can often be done in a weekend. We’ve outlined the steps below, but before you start digging it’s important to know exactly what kind of look and feel you want. Do you want a regular, geometric path to add some drama and stately elegance to your home? You’ll want to buy pavers that are already cut into same-sized squares or rectangles, or have a mason do the cutting for you. If you want a more organic, free-form feel, you’ll want to stick with irregularly shaped flagstones. In this case, you’ll want to think about how far apart you want to space the pavers. Do you want strips of grass to grow between them, or have them spaced out in a bed of sand for a zen garden-like feel? Or do you want them grouped closely together and mortared? All are important considerations that need to be thought through thoroughly before you begin your project.
After you’ve decided on your concept, it’s time to get to work!
1. First, outline your flagstone path or patio. You can do this by using an edger and bender board to create an outline, or you can simply use spray paint to mark off the area. If you want to make sure weeds or grass don’t grow between pavers, you’ll want to lay down some filter paper next. If you want grass or plants to grow, you can skip the filter paper step.
2. Next, dig a shallow trench within this marked off area, about 3-4” deep. This will account for both the thickness of the stones, as well as the thickness of the sand base.
3. Fill the trench with a layer of sand, just enough so that it just surrounds and holds the entire stone. Then, begin laying the flagstones in your desired configuration, pushing the stones down into the sand and pounding them with a rubber mallet to make sure they’re well set and flush with the surrounding earth.
4. Check to make sure the stones are level. Use a mallet to push the stones down at any high points, or lift the stones and add more sand if there are areas that are too low.
5. Finally, it’s time to fill in the gaps. You can do this with more sand or with gravel, dirt, or mulch. You can also fill it with mortar if you don’t want to deal with potential weeds growing through the other materials. If your pavers are right up against one another, we recommend using dirt, sand or mortar rather than mulch for a more uniform look.
That’s all there is to it! Your DIY patio or path is not only cost-effective, your friends and neighbors will be really impressed when they find out you created such a beautiful feature yourself. Got a question about what kind of flagstones would be best for your yard? Drop us a line right here!