Flagstone Patios, Walkways, and Walls

A guide to choosing and using flagstone in your backyard

Reviewed by Johnathan Brewer

Flagstone adds permanence, strength, and durability to a landscape and creates a natural hardscape element that otherwise might include plants. Flagstone is a popular design choice for patios and walkways. Learn about this versatile stone and if it's right for your home.

What Is Flagstone?

Flagstone is a sedimentary stone that's sliced into different pieces and layers. Types of rock used for flagstone include sandstone, bluestone, slate, quartzite, and limestone.

Flagstone Characteristics

Flagstones are large, flat slabs of stone milled in thicknesses of 1 to 3 inches. Flagstone is a sedimentary rock, often made of sandstone. It is commonly available in the colors red, blue, and brownish-yellow. A product of nature, no two stones are exactly alike.

Tip

When landscaping, complement flagstone with other types of decorative stone such as natural boulders, cut stone, cobblestones, veneer stone, and crushed or rounded gravel.

Installing Flagstone

Use flagstones that are at least 1-1/2 inches thick as stepping stones or patio flooring. With the latter, flagstones can be laid directly in soil or a bed of sand. Thinner slabs should be laid in wet mortar or concrete to prevent cracking when stepped on.

The spaces between irregularly shaped flagstones can be filled with pea gravel, polymeric sand, or ground cover plants like Dymondia margaretae, creeping thyme, and dwarf mondo grass.

When flagstone is positioned in a tight-fitted design or pattern, mortar is used to fill in the seams and gaps. Butting pieces close together and using mortar creates a smoother, more even surface, which is ideal for patios.

Flagstone Applications

Flagstone can be cut into uniform rectangular shapes or more random, irregular pieces that can be arranged like a puzzle. Unlike other stones, a roughened surface texture offers good, safe traction—especially when wet—making them an ideal choice for outdoor flooring.

Flagstone Patios

Patios can have flagstones separated by low-growing ground cover or pea gravel rather than cement or mortar. If the flagstone is for a patio, any furniture on top of the stone should be flat, even, and steady.

Flagstone Walkways

A flagstone walkway safely guides you into a house, while a patio or path entices you outdoors, into a front or back yard.

Before choosing flagstone for a walkway, though, think about the users. Are there any relatives on walkers or in wheelchairs? A smooth and even pathway, such as concrete pavers or poured concrete, will make the walk from the street or curb to your front entry much more manageable. Some cities have building code requirements for ease of access and entry.

Flagstone Walls

Flagstone can be stacked to create a natural-looking low wall. Available in a wide range of colors—from white sandstone to black slate—flagstone can blend with other surfaces and hardscape elements in a landscape.

Flagstone walls can be built dry-stacked or mortared. One advantage of mortar, which is like glue that holds stones together, is that it creates stronger freestanding walls.

Cost of Flagstone

If you're installing your own flagstone, home centers and nurseries sell flagstone that you can take home or have delivered in bulk. Thirty square feet of flagstone costs around $750 to $850, not including delivery charges.

The cost to have a professional install a flagstone patio runs from $15 to $27 per square foot, including materials and labor.

How to Pick Flagstones

Visit a local stone yard to find out what's available and what you find most appealing for your particular project. The good thing about choosing stone from a local source is that it is more likely to blend with the environment and will be available if you run out. If you build additional outdoor hardscape features, those stones or similar pieces will be available at your local dealer.

Frequently Asked Questions

Can I install a flagstone patio myself?

You can install a flagstone patio by yourself. One difference between using flagstone and other hardscaping materials is that flagstones are large and heavy, so they are difficult to install.

What are the cons of using flagstone?

Though flagstones have many advantages, one major con of using flagstone is that they do not present a flat, smooth top surface. While it's possible to flip the flagstone over to choose the best side, invariably neither side will be perfectly flat and smooth.

Is flagstone difficult to maintain?

Flagstones are moderately difficult to maintain. The wide joints between the stones collect organic materials, creating a growth environment for weeds. Mortaring between the flagstones controls weeds, though.

How does the cost of a flagstone patio compare to a concrete patio?

A flagstone patio will cost about three times more than a concrete patio. The price of flagstone materials is much more than poured concrete. Plus, more hours of skilled labor are required to install the flagstone patio.

Read the original article on The Spruce.