Flagstone vs Slate: What’s the Difference?

When creating a patio for your backyard, one of the most crucial decisions is what material you will use for the flooring.

With so many different stones available, the decision for your patio can feel overwhelming. And although there are so many different materials available, many come down to the same two choices - flagstone vs slate. While both of these stones make for a beautiful finish for any patio, there are pros and cons that are essential to know before making your final choice.

So, what is the difference between flagstone and slate? We are sharing all the details of each material below so you can make the final decision for your patio design.

What Is Flagstone?

Flagstone is a broad term used to describe a range of sedimentary and metamorphic rocks. These rocks are called flagstones because they can be easily split into flat segments that are used to pave patio walkways and build rock walls, in addition to other home applications. Essentially, when a stone is called a flagstone, it doesn’t point to one specific stone, but instead any stone that is suitable as a paving stone. 

Advantages of Flagstone

One of the main benefits of using flagstone for a patio is that it comes in a range of styles and colors. This large assortment allows for your unique customization of your patio, fitting just the design you had in mind with a range of stone options.

Additionally, flagstone is an incredibly durable material. It is made up of rough substances that are built to withstand harsh weather conditions, holding up for years to come.

Disadvantages of Flagstone

The main disadvantage of flagstone is how you must prepare to install this material. Since the type of stone comes in a range of sizes and thicknesses, laying it down on an even surface for a patio takes a great deal of time and expertise to install properly. 

What Is Slate?

On the other side of the slate vs flagstone debate is slate.

Slate is a type of rock that many find difficult to differentiate from flagstone, and for a good reason. In fact, slate is a type of flagstone used in various outdoor applications, as it is easy to cut into thin layers and is often readily available and affordable. This is because it is the metamorphosed form of the sedimentary rock, shale.

Advantages of Slate

A key reason many homeowners opt for slate for a patio is that it is both waterproof and heavy-duty. Due to the texture of this material, any time of water, including rain, will not erode the surface. This is due in a large part to the texture, which greatly enhances the durability of this stone. With this in mind, owners don’t have to worry about fixing slate tiles too often on their patios. 

Disadvantages of Slate

While slate is equipped to withstand water, it typically offers a glossy shine that can become slippery. Additionally, due to this glossy finish, the stone can get especially cold in the wintertime. These are two important considerations when considering your comfort and safety. 

What Is Shale?

Shale is fine-grained sediment and is a key base component for slate. This material is formed when shale sediment morphs into rock after prolonged exposure to pressure under the earth’s crust. This shale is made from organic matter that settled into the mud and built up to a point where the pressure turned the matter into shale. Due to a large amount of organic matter found in shale, it is a great source of natural gas. 

Metamorphism: How Slate Is Formed

slate vs flagstone cost

To better understand slate, we must define metamorphism. 

Metamorphism is the process in which shale is converted to slate. This happens over time, as the geological processes cause shale to move deeper within the earth’s crust. With this, the pressure and heat increase, where shale is exposed to extreme conditions that cause it to undergo chemical and textural changes. With these changes, shale eventually changes into the metamorphic stone, slate. 

Slate vs Flagstone Cost

Beyond the fundamental difference between flagstone and slate, there is also the slate vs flagstone cost to consider. Let’s break it down.

Cost of Slate Tile Flooring

With such a wide range of slate materials available, the cost can range anywhere from $5 to $20 per square foot. The final cost will depend on the origin of the material, as well as the density. Additionally, this material will have higher installation costs than other materials available. 

Cost of Flagstone

With naturally beautiful colors, with shades from sand, to gray, red, and purple, there’s a great appeal to flagstone. With a rustic charm and a durable design, it can be more affordable than other types of stone, usually costing $2 to $6 per square foot on its own. That said, some flagstone varieties can cost $10 to $15 per square foot. While certain flagstone types will cost more, the cost of flagstone vs slate still tends to be in favor of flagstone when it comes to remaining within budget.


With all the information on flagstone vs slate patio designs, it’s time to decide which is best for your next home project.

For a trusted partner to help navigate the flagstone vs slate debate with you, and implement these beautiful stones within your patio project, trust Stone Center as the local flagstone supplier in Ohio for the job. To begin your next landscaping project, contact us today to start the process.