How to Cut Slate

Whether you’re embarking on a new landscaping project, building a pool table, or installing a slate floor, there may come a time where you’ll need to learn how to cut slate. Working with slate can be a little intimidating thanks to the fact it’s both hard and brittle.

Thankfully, learning how to cut slate isn’t as difficult as it may seem at first, and the tips in the guide below will have you feeling confident in your ability to tackle your next project.

What You’ll Need

When it comes to cutting slate, there are a few different options you may wish to try. I’m partial to using power tools to cut slate as the results are much cleaner and easier to duplicate, and that’s what we’ll be focusing on today. Here’s what you’ll need:

*You’ll only need these two items if you’re going to cut the slate the old-fashioned way, without the help of power tools.

Step I: Sorting the Slate

Slate comes in all different shapes, sizes, thicknesses, and colors. An easy way to save time and make this project easier to manage is to sort your different slate pieces before you begin.

That way, you can match slate pieces based on color, shape, size, and thickness to ensure that your results look polished and uniform.

You’ll also be able to identify “bad” pieces that shouldn’t make it into your final project. Like a piece with a thin middle that’s going to break soon after the job is complete, or a piece that doesn’t come close to matching the color of the other pieces.

Step II: Measuring the Project

Once you’ve sorted through your different slate pieces, you’ll want to make your measurements using a tape measure.

Once you’ve measured the dimensions for each piece, you need to cut. Use a carpenter’s pencil and straight edge to mark the lines on the top side of the slate.

If you were going to be using a hammer and chisel or a slate cutter to cut through the slate, you’d mark the back side of the slate and make your cut from bottom to top. But, since we’re using power tools, it’s much more important that the slate has a nice flat bottom to lay on as you cut.

Step III: Cutting the Slate (With Power Tools)

With your slate marked, you’re almost ready to begin cutting.

Slate generates tons of dust as you cut, which can irritate your eyes and lungs, so it’s also helpful to soak your slate pieces in water for a minute or two before you begin cutting.

Even if you soak the slate before cutting, you’re still going to run into some dust, so many sure you’re wearing proper safety gear. I always reach for a pair of safety goggles, gloves, and a respirator.

Now for the cutting.

First, you’ll want to secure the slate to your workbench. For this step, I usually clamp the slate to my workbench with the side I’ll be keeping on top of the workbench and the side I’ll be cutting hanging over the edge of the bench.

If you’re using an angle grinder, turn the grinder on, grasp the guide handle with your spare hand, and hold the grinder so that the blade makes a right angle with the top of the slate. Begin your cut at the end of the slate that’s closest to you and slowly allow the saw to work it’s way through the slate, applying very light forward pressure as the saw cuts.

If you’re using a circular saw, the premise is the same. First, make sure your saw is equipped with a carbide tipped blade. Then, pull back the blade cover, and turn on the saw. Begin your cut at the side of the slate closest to you, and slowly allow the saw to work its way through the slate.

Step IIIA: Cutting the Slate (With a Hammer and Chisel)

If you don’t have an angle grinder or circular saw available, you can still cut the slate with the help of a hammer and a cold chisel.

First, place your straight edge on the line you’ve marked and use your chisel to score the slate. Applying firm pressure as you score the slate will help the slate break more cleanly when you’re finished.

Next, take your chisel and place it inside of the groove you’ve scored, and begin to tap lightly with the hammer across your scored line. Once you’ve chiseled across your line, you should be able to pick the piece of slate up and break it cleanly along the line.

If the slate won’t break, make another pass with your chisel and hammer and try again. Repeat this until you get the slate to break cleanly at the line you’ve scored.

Final Word

While it may seem intimidating at first, learning how to cut slate is quite easy. Whether you’re using an angle grinder, a circular saw, or just a simple hammer and chisel, you should be able to make quick work of your next slate project by following the tips 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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