Masonry 101: How to Cut Flagstone

Flagstone is an attractive, flat stone that’s most commonly used to pave outdoor walkways and patios.

Though it might not seem like it, it’s actually pretty easy to cut and install flagstone by yourself, even if you’re a home DIY beginner.

Because of the style that most flagstone walkways and patios utilize, you usually don’t have to make super precise cuts. Approximate cuts work just as well.

By the time you’re done reading this guide, you’ll feel completely comfortable cutting flagstone yourself, using one of the three best methods.

Here are the best ways how to cut flagstone with ease.

What You’ll Need

There are three main ways to cut flagstone. Each requires a different set of tools:

Method 1: Hammer & Chisel

Method 2: Circular Saw

Method 3: Masonry Saw

Method 1: Hammer & Chisel

The simplest way how to cut flagstone is with a hammer and chisel.

Step I: Measure and Mark

Measure the length of the cut and make a mark with the chalk.

Remember that although the measurement doesn’t need to be exact, it should still allow enough space for mortar to be added.

Step II: Create a Groove

Use the hammer and chisel to first score a line across the measurement mark.

Then continue along the line with slightly more pressure to create a shallow groove. Continue working along the groove by digging slightly deeper with each pass.

Step III: Tap Until It Breaks

The flagstone will break on its own, so don’t rush this part of the process. Continue tapping along the cut line with the hammer and chisel until the material breaks into two.

Method 2: Circular Saw

A circular saw, fitted with a masonry bit, makes cutting flagstone a little easier.

Step I: Measure and Mark

Take your measurements and mark the flagstone with chalk.

Once again, it’s important that all marks and measurements take the inclusion of mortar into consideration.

Step II: Cut a Deep Groove

Prepare the flagstone for the cut.

If it’s a smaller piece, make sure it’s held in place with clamps. Remember to always use a masonry bit on the circular saw.

A masonry bit isn’t designed to completely cut through the material. Instead, it works much like the hammer and chisel method to create a deep score or groove on the flagstone.

It’s important to allow the weight of the saw to do the work – never press down onto the saw to encourage deeper or faster cutting.

Step III: Tap with Hammer

After a deep groove has been made, tap along the bottom edge of the cut portion with a hammer. The piece should easily break away. You might have to use the chisel in the groove for some tricky pieces.

Method 3: Masonry Saw

The absolute easiest, although most expensive, tool to cut flagstone with is a dedicated masonry saw.

Step I: Measure and Mark

Measure and mark a cut line with chalk, leaving room for mortar.

Step II: Start the Cut

Set up your masonry saw or wet saw with a diamond masonry blade. Begin the cut by slowly moving the flagstone into the blade.

Step III: Let the Saw Do the Work

Don’t push the flagstone into the saw. Instead, let the saw do all the work. A powerful masonry saw will actually pull the flagstone through it at its own pace as it cuts.

Which Method is Right for You?

Each of the three ways how to cut flagstone described above has its place.

The hammer and chisel method, for example, is best for making approximate cuts on thin pieces of flagstone.

The circular saw method, on the other hand, is best for making approximate cuts on thicker pieces of flagstone, such as those too thick to break with just a hammer and chisel.

Finally, the masonry saw method is the best for making more accurate, exact cuts as well as making thicker or longer cuts.

If you’re working with large pieces of flagstone that you don’t want accidentally broken, it’s almost always best to hire a professional.

Stay Safe

Wearing the right safety equipment is imperative for all three of these methods.

However, it’s most important when using a masonry saw because of the large amount of dust and noise created.

You should wear sturdy work gloves and eye protection for all three methods. It’s smart to also wear ear protection and a dust mask when using a masonry saw to cut flagstone.

Final Thoughts

It’s actually really easy to learn how to cut flagstone.

And the fact that most home DIY projects with flagstone only require approximate measurements means that exact accuracy typically isn’t even necessary.

You’re sure to efficiently complete your flagstone project by using one of the three cutting methods detailed above.

About Gus Donaldson

I built houses for over 30 years and recently retired. I've made lots of mistakes and hopefully teach you not to make the same ones. I still love to build and have a garage workshop that I use for hobby projects like the walnut bookshelf I made for my wife. I like to write and let people know that working with your hands and tools does not need to be intimidating.

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