How to Cut a Quartz Countertop

Measuring the Countertop and Marking Your Cuts

Measure the surface area where you're installing your countertop. Use a retractable measuring tape to measure the length and width of your countertop. Draw out your surface on a piece of paper and label the length of each side so that you have a reference while cutting the quartz. Use the metal lip at the end of your measuring tape to attach it to the edge of your cabinets if you're working alone. It doesn't matter if your drawing is to scale or not. The important thing is that the measurements are correct so that you can easily reference them when you're cutting your quartz.

Add an additional 1.5 inches (3.8 cm) to the edge of your cabinets for your overhang. Most quartz countertops don't line up flush with the cabinets. Typically, there's a small section of quartz that extends past the edge of your cabinets or table. The average distance for an overhang is 1.5 inches (3.8 cm), but you can choose to add between 1–6 inches (2.5–15.2 cm).Tip: If you want your countertop to be flush with a stove or refrigerator, don't add overhang measurements to the sides where you'll insert an appliance. The maximum length allowed for an overhang on a kitchen island or extended section of countertop is 12 inches (30 cm). Anything bigger than that is structurally unsound.

Mark the location of the sink on your cabinet with a marker. You need your sink to rest directly above the water lines underneath your countertop. Measure the dimension of your sink, and draw lines on the top of your cabinet to indicate where your sink will go. This way, you'll be able to check if the sinkhole in your quartz matches the opening in your cabinets before affixing it. Add these measurements to your illustration. Some sinks come with a template that you can outline on your countertop to help you cut. When you're installing your sink, you'll rest it in on top of a fitted hole that you'll cut out for it, so don't measure the very edge of your sink. Instead, measure 2 inches (5.1 cm) past the edge to give you room to access the sink slots.

Make a template for more precise cuts. Take strips of balsa wood or rigid cardboard and lay them along the edges of your existing countertop. Be sure to line up the edges precisely. Then, hot glue the strips together to create a template. When the glue dries, you can just lift up the template and lay it on top of the quartz.

Set your quartz upside-down on a stable work surface. A cutting table capable of handling a lot of weight is preferable, but you can also set up sawhorses as well. You're going to want to mark the underside of the quartz slab so that there are no visible markings left on the top of the surface.Tip: Quartz is incredibly heavy. Make sure that a sawhorse can handle the weight before putting your precious countertop on top of it.

Use a grease marker and straight edge to mark all of your cuts. Lay your template on top of your quartz slab, then carefully and slowly trace along the line with a grease marker. However, it doesn't hurt to double-check your measurements after you trace the lines,even if you used a template. When you measure out the section for your sink, mark your lines 0.5–1 inch (1.3–2.5 cm) closer to the center of the sink. You'll need some extra space to smooth your edges and you don't want to risk cutting too much off to begin with. You want to measure out every section of your countertop before cutting. This way you'll be able to visually inspect whether you've made an incorrect measurement and double-check your length and width before you permanently remove sections of quartz.

Using Your Circular Saw for Straight Cuts

Put on your protective eyewear and respirator. The dust created when you cut quartz is toxic, and can damage your lungs and eyes if you're exposed to it. Wear a respirator and airtight protective eyewear when you're about to cut your quartz. Work in a well-ventilated area, preferably outdoors.

Attach a diamond saw blade to your circular saw. A continuous diamond saw blade will give you the cleanest cuts. If you're going to use a saw blade with slots, they should be extremely narrow. If you need to switch your blade out, release the arbor nut in the center of your circular saw, and twist it until it's loose. Carefully remove it and slip your new blade over the arbor nut and tighten it in place. You may need to remove a blade guard before placing your new blade over the arbor nut.

Set up a straight edge parallel to your longest lengthwise cut with clamps. Use a leveler or framing square if you have one. Place your straight edge next to a line that you plan to cut and attach it to your quartz using clamps. Place the edge of your circular saw's base plate along the straight edge to see if your grease marking line aligns with your saw's guiding line. If it doesn't, adjust your straight edge accordingly.Tip: On most circular saws, the distance from the guiding line to the edge is 1.5 inches (3.8 cm). Keep this in mind when you set up your straight edge for the first time. Make your longest cut first so that you have a much smaller piece of quartz to work with. This will make the remaining portion of you slab easier to move and brace.

Adjust the blade in your circular saw to cut through the quartz. You want your blade to go all the way through the bottom of the quartz. Lift the blade guard and use the lever next to your saw's handle to adjust the blade so that it sticks out roughly 1–2 inches (2.5–5.1 cm) past the bottom of your slab. Lock your blade guard in place and rest the base plate on top of the quartz near the area you're cutting.

Check your guiding line and pull the trigger on your saw to start cutting. Put both hands on the top handles of your circular saw, and line up the guiding line on the base plate with your grease marker line. Pull the trigger on your circular saw and wait for it to reach full speed before pushing it forward slightly. Keep your straight edge on the right side of your circular saw's handle. This will ensure that your saw doesn't go sliding away from the guiding line when you apply pressure to it.

Cut all the way through your grease marker line. Let the saw do most of the work. It will naturally move forward as it cuts, so you shouldn't be pushing very hard. If your saw blade begins to kickback or smoke, release the trigger on your saw and wait 1-2 minutes for you saw blade to cool off.Warning: The dust that will fly off from your circular saw is toxic, and you should avoid it as much as possible. Smoke is more likely to occur if you're using a dry saw. A wet saw is going to prevent heat from building up, but you're unlikely to have a wet saw laying around your workshop. Consider renting a wet saw if you want to avoid a smoking blade.

Repeat this process to make all of your straight cuts. The straight edge and circular saw will work for every straight cut that you have to make. Repeat this process until you've cut through every straight line on your slab of quartz.

Drop-Cutting Your Sink Space

Set up your guide rail for cutting with a plunge saw. Set up your plunge saw's guide rail on top of your guiding line. You can affix the guide rail to the quartz with clamps if you'd like, but a plunge saw guide rail is usually designed to rest on its own. Your guide rail will have an opening in the middle for you to see your grease markings. If you have a sink with curved edges, you won't be able to use the plunge saw for the entire job. Instead, use painter's tape and wrap it around the edges where you're going to cut, and then set up your guide rail to cut a square out of the middle of your sink's outline. A plunge saw is also known as a track saw.

Line up the back of your saw blade with any corner of your sink's outline. There is a slot or marker on the side of your plunge saw where your blade ends in the back. Release your blade all the way up so that it isn't sticking out through your base plate, and line up the corner of the sink with this line. You'll usually have about a 1 inch (2.5 cm) margin of error. A lot of sinks don't have form-fitting lips that you need to cut perfectly into.

Attach your plunge saw to the guide rail. The guide rail that comes with your plunge saw has groves in it for you to insert the plunge saw. After you've lined up your guide rail with the grease marking, put your saw on top of the guide rail and lock it into place if it has a locking mechanism.

Drop your plunge saw slowly and begin to guide it forward. Put both hands on the handles on top of your saw, and slowly lower the blade into your quartz. Guide the saw forward slowly as you cut and stop once you've reached the corner where your next side begins. Repeat this process for each side of the sink.Warning: When you've made all four cuts, you'll have a big chunk of quartz falling out. Either put a pillow down or have a flat work surface set up so that your quartz doesn't crush your feet or damage the floor when it drops. If your sink is circular or round, you'll still want to cut a square out in the center. This will make working away the rest of the material easier because you'll have room to maneuver your quartz grinder.

Use a grinder to work away the excess sections of a circular sink. Use a diamond blade and wear your protective gear when working with an angle grinder. Hold it with both hands and slowly work through the excess pieces by keeping your grinder flat and parallel to the inside edge of your sink. Using a grinder can be difficult if you've never done it before. Practice on a spare piece of quartz that you don't plan on using to get used to how it feels.