Everything You’ve Always Wanted to Know About Flagstone

Lawrence Bonk
Written by Lawrence Bonk
Updated April 19, 2022
A family eating breakfast in the backyard
Photo: Mint Images / Mint Images RF / Getty Images

Flagstone comes in many forms and has become a go-to choice for jaw-dropping exteriors

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It’s tough to turn your outdoor space into a year-round party pad if your yard is on the plainer side. Bare patches of grass, after all, are not especially inviting. Your best bet is to hire a professional landscaper to discuss alternatives, but what are your options? One of the most popular landscaping choices in recent years is to lay down flagstone to form walkways, patios, and more. Flagstone is strong, extremely versatile, and looks fantastic. But what, exactly, is it?

What Is Flagstone? 

Flagstone is not a type of stone; it’s a blanket term referring to many different types of rocks. The term refers to the size and shape of the rocks, as flagstone breaks from larger pieces of stone into flat sheets of varying thickness. A stonemason turns many different rock types into flagstone, including sandstone, shale, limestone, quartzite, marble, granite, basalt, and others. Flagstone can be relatively soft if made from sedimentary rocks, or incredibly tough if made from igneous or metamorphic rocks.

What Is Flagstone Used For? 

Flagstone gives an outdoor space a pleasing rustic look, bringing with it many uses. Flagstone patios have become a popular choice in recent years, as have flagstone walkways. Flagstone is also tough enough to withstand the weight of an automobile, so many homeowners opt for flagstone driveways instead of boring, old concrete. Some roofers even use flagstone to make shingles. In other words, this is a highly versatile material.

What Are the Types of Flagstone?

Two boys playing in the stone walkway
Photo: Cavan Images / Cavan / Getty Images

As previously mentioned, flagstone is a catch-all term referring to any number of rocks that flake into flat sheets. Flagstone breaks down into two types: patio flagstone and select/stand-up flagstone. Patio flagstone is typically on the smaller side (about 12 to 18-inches around). 

These smaller pieces make for great walkways, stepping stones, and, of course, patios. Next, select flagstone, otherwise known as stand-up flagstone, is slightly thicker and much larger, with a circumference of 18 to 36-inches. Select flagstone pieces are for stacking, making them an excellent option for wall caps, countertops, and other applications. 

However, there are numerous types of flagstone for primarily aesthetic value. 

Sandstone Flagstone

This type of flagstone—primarily made of sandstone—features a distinctive rough-textured look and comes in a full range of colors, from pale sand to dark red. Even cooler? Some sandstone flagstone pieces include stray plant and animal fossils. 

Quartzite Flagstone

Known for its superior durability, quartzite flagstone is the perfect option for heavily trafficked areas. A stonemason mixes sandstone and quartz to create quartzite flagstone. It comes in a wide array of color options, from silver and gold to green and blue. 

Colorado Red Flagstone

Colorado red flagstone stands up well to harsh weather, so it’s an excellent choice for areas with either scorching summers or frigid winters. As the name suggests, the colors range from red to purple. 

Bluestone Flagstone 

Bluestone flagstone is highly resistant to freezing temperatures, though it does not stand up too well to saltwater. It boasts a natural non-slip finish, making it a great choice for poolside areas. Bluestone comes in various shades of blue and gray.

Advantages of Flagstone

There are several unique advantages to flagstone that make it a desired paving choice. 

Beauty and Variety 

Flagstone comes in nearly every color of the rainbow, with naturally occurring patterns to add a truly distinctive look to your renovation project. You can mix and match types for unique and breathtaking color schemes. The sheer variety of available types ensures that each flagstone project has its own look and feel.

Fairly Easy to Install 

Most flagstone types are easy to install, as a qualified pro lays it directly on top of a layer of sand or gravel. This is dry-laid flagstone. Some homeowners opt for mortared flagstone, which lays in a bed of mortar. Mortared flagstone is more labor-intensive than dry-laid flagstone, but makes up for the extra effort with increased durability and longevity. 

Versatility 

Flagstone is just thin slabs of stone, making them incredibly versatile; you can use flagstone all over your property for entirely different purposes. It’s an excellent option for both indoors and outdoors, after all.  

Safety and Durability 

Most types of flagstone are naturally slip-resistant, which is why they show up so regularly as walkways and surrounding poolsides. Flagstone also tends to resist freeze-thaw cycles, upping its durability. Most flagstone installations should last 30 years with proper care and maintenance. 

Disadvantages of Flagstone 

Flagstone is not perfect, and it does carry some unique disadvantages. 

Thinner Pieces Can Break

Thinner pieces of flagstone can break if you aren’t careful. Softer flagstone types, such as sedimentary rocks, are particularly prone to breaking. If you lay down flagstone to form a heavily trafficked walkway or a driveway, ensure the rocks are thick enough to stand up to abuse. 

Difficult to Source Replacement Pieces

If your flagstone pieces do break, it’s often a challenge to source an exact replacement. Flagstone is naturally occurring and minimally processed, so quarries produce pieces that vary in color, design, and thickness. If you are looking for replacement pieces, reach out to the stonemason who sourced your original pieces. 

Needs Regular Cleaning and Sealing

You should regularly clean and seal your flagstone to ensure a long lifespan. Sealant helps the flagstone repel water and helps to fill in any pores. Apply a sealant once every year. As for cleaning, outdoor flagstone can get dirty easily, ruining the material’s natural elegance. Clean the flagstone twice a year with a vinegar-based solution or a flagstone cleaning solution. 

How Much Does Flagstone Cost?

Flagstone is relatively affordable, though the cost of flagstone varies, depending on the type of rocks used. This material costs $2 to $6 per square foot, though you should also account for labor at $13 to $16 per square foot. These labor costs can add up, especially with a large project, such as building an entire patio. The cost of a flagstone patio ranges from $750 to $8,400, depending on square footage, installation type, and materials needed. 

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