How to Cut Stone – For Beginners

Stone slabs are one of those beautiful alternatives to your normal concrete floors. Many people steer away from doing their own stone work because they assume it’s too difficult or requires too much technical expertise. True, it does require a lot more in terms of plain ol’ hard work, as the stone itself can be quite heavy. But aside from the sweating and the muscle ache the next day, it’s not all that difficult to do. First step is the easiest one (maybe) – picking out your stone. Recently I got my hands on some nice granite slabs – about 3 tons of it. The thing about this batch of stone was that they were all pre-cut into funny fan shapes. They were obviously made for the

diy stone slabs

My finished stone landing

fan pattern, but because I didn’t want this particular pattern but instead wanted a normal rectangle pattern, I had to cut each stone into a rectangle.

This brings us to step number 2. Usually you’ll want to get stone that’s already in the shape and size you want it. But on occasion you may end up with stone that needs to be “customized”. This could be due to not being able to afford the ones you wanted or you couldn’t find the ones you wanted. There may be other reasons as well. The point is that you should know how to customize your stone should the need arise. Like any other material, stone can be cut. The obvious issue that arises with stone though, is that it’s damn hard! And depending on the kind of stone, the hardness will vary. Granite for example, is quite hard, whereas limestone is

fan shaped granite

Original "fan-shaped" stone

fairly soft. It’s not like you can just take a normal circular saw and rip through the stone. So how do you do it? Well, the age-old principle of cutting any kind of material is to do so with a material that’s harder.

I used to wonder why diamond blades were “segmented”, or “not even sharp”. I mean, the thing doesn’t even look sharp – how is it supposed to cut anything? Well, this may sound like a dumb question, and if you know the answer to this, good for you. But some of you may not know this if you were never taught. The sharper the blade (or the teeth of the blade) is, the more prone to wear and chipping it will be. In the case of stone-cutting, if you were to use a diamond blade that was as sharp as a razor, it would go from being that to looking like a millstone in a matter of seconds. This is the second prerequisite to cutting material as hard as stone. Not only does the cutting blade need to be harder than the material being cut, but the “point of contact” also needs to have sufficient area to ensure maximum wear-resistance.

You probably won’t have to worry about this though, as diamond blades are manufactured with this in mind. So back to how you can cut these things into the shapes you want. You may have heard of people scoring and whacking pieces of stone with chisels and getting good results this way. Ok, this may work for softer kinds of stone like sandstone etc, but it almost certainly won’t work for harder stone like granite. For harder stone you’re gonna have to cut about a 3rd or at least a 4th into it before applying the chisel. The tool of choice for stone-cutting is probably a wet saw. A wet saw sprays water out of a nozzle directed at the work piece while you’re cutting through it. This has 2 positive effects: It provides lubrication for smoother cutting and longer blade life, as well as keeps the often toxic dust from going all over the place.

laying stone on mortar bed

Stone-laying phase prior to grouting

There are of course what you call dry saws as well. These are simply wet saws without the water function. If you do use a dry saw, it’s best to have a strong fan blowing the dust away from you while cutting. Certain stone contain a mineral called silica which can cause health problems like cancer and bronchitis if inhaled over long periods of time. So to recap:

1. Procure your stone. You should if possible, get the shape you want from the beginning. If you do, you can skip step 2 and go right into the laying.

2. Cut your stone to the size and shape you want. Use a wet or dry saw and cut about a 3rd or 4th into your stone. Then use a stone chisel and mallet, and slowly, evenly, “suggest” to the stone that you want it to break at the cut-line. If you rush this part, you run the risk of breaking the stone in the wrong place, ruining your whole work piece and wasting your time. Take your time and don’t push it. If you’re really in a hurry and the stone doesn’t seem to want to break, set the blade to cut deeper. This will initially take you a little longer to cut deeper, but your chiseling job will be considerably easier and will save you time in the long-run.


Comments are closed.