How To Cut Concrete

Whether you need to fit pavers together or trim up a patio, it could very well require cutting concrete with a saw. It’s a physically demanding job, but it can be manageable if you choose the correct tools and practice key techniques.

If you’re embarking on a concrete project, here’s how to set yourself up for success with cutting concrete.

What Tools Do You Need for Cutting Concrete?

To cut concrete, people commonly use a handheld circular saw and diamond-bit blade, but you can also use:

• A table saw, which makes it easier for beginners to make straight or mitered cuts;
• An angle grinder, for small and detailed projects like thin veneer and pavers; and
• A chainsaw for larger projects.

Some saws are classified as wet saws, which require a water source. They are great for helping to keep dust down, especially indoors where there is less ventilation. The downside is that they are less maneuverable. Whichever saw you use, you will also need a diamond-bit blade.

What Type of Saw Blades Do You Need for Cutting Concrete?

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Diamond-tipped blades are required for cutting concrete. Choose a blade hardness that matches the material you’re cutting.

“If it’s relatively soft, coarse concrete such as that [is] found in wall block, you want a blade that won’t wear down quickly,” says Jeremy Martin of Willow Gates Landscaping. “If you’re cutting hard, dense concrete with a finer aggregate such as concrete pavers or some natural stone, you need a blade that will wear down faster to expose fresh diamonds to continue cutting.”

How To Cut Concrete

If you are concrete saw-cutting concrete:

• Prep the area by clearing it of debris, especially metals that could get caught in the blade.
• Adjust the saw for the desired depth of the cut.
• Mark the lines you want to cut using chalk, a marker, paint or a grease pen. “Make sure to mark these spots completely and clearly to prevent missing them when concrete dust goes everywhere,” says Brandon Walker, superintendent at ASAP Restoration.
• Put on safety gear, including eye and ear protection. Wear a respirator to prevent inhaling dust. A protective suit can also help you avoid getting covered in dust and debris.
• If you’re making wet cuts, keep a consistent water supply running, preventing the saw blade from overheating, binding or warping. For dry cutting, let the blade cool down every 30 to 45 seconds.
• Before placing the blade on the concrete, let it get up to speed, then lower it onto the surface slowly to prevent it from binding.
• As you cut, keep your blade squared up with the line of your mark.
• Once you’ve finished your cut line, release the trigger and let the blade spin down inside the cut before removing it from the cutting area.
• Clean up the dust. “Vacuums are best for cleaning up concrete dust because they prevent spreading and aeration caused by brooms while sweeping,” says Walker.

Also, whenever possible, bring the saw to the work area rather than carrying the product to the saw, says Martin. “Paving and wall materials are heavy, and it’s physically demanding to move them to the saw and back to where they will be installed.”

Cutting Different Types of Concrete

If you’re cutting a curve, Martin recommends forming your line using pex, hose or fiberglass tent poles. “When cutting wall block, a handheld saw may not cut the whole way through a block,” says Martin. “In this situation, mark the block, then cut as far as the saw blade will reach. Then flip the block, and cut the remainder.”

Dos and Don’ts for Cutting Concrete

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When cutting concrete, always:

• Wear safety gear, including hearing, eye and respiratory protection.
• Check the condition of your blade.
• Choose the correct type of blade for the concrete you are cutting.
• Clean up wet slurry before it dries. If it dries, removing it could cause damage to surfaces.
• Actively control dust.

“Unless it’s a very shortcut, dust control is essential,” says Martin. “Cutting generates a lot of dust, some of which is harmful respirable crystalline silica.”

Most saws have a built-in water attachment that will control the dust by wetting it, and some have built-in vacuums like those from IQ Power. Another option is a central dust collector such as those offered by Dust Killer Tools.

“Using a vacuum for dust control will result in a much cleaner job site, without a huge cloud of dust drifting over the work area, neighboring homes and cars,” says Martin.

Some mistakes to avoid include:

• Using a wet blade without using water, which will damage it.
• Cutting concrete in confined spaces without proper ventilation.
• Using dull blades, which will lower the quality of the cut.
• Forcing the blade. If it isn’t cutting properly, instead make multiple shallower passes.
• Cutting through objects embedded in the concrete, like rebar and electrical wires.
• Pulling the saw out of the cut before the blade has spun down.

“Poor planning is also a common issue when dealing with slab cutting,” says Walker. “Measure everything until you are positive that it’s right, then triple check again. You can only make the cut once, and with concrete it isn’t easy to fix mistakes.”

When to Hire a Pro

If you are unsure of your ability, or if it feels dangerous, then call a pro. You might also hire a pro if you have to do major cuts or are unsure about crossing over plumbing and electrical lines.

“Saving money by doing things the DIY way is great, but not if it comes at the cost of an insurance claim for water damage when you cut through a pipe, or a blackout when you slice the electrical line,” says Walker.

FAQs

How long do diamond blades last for cutting concrete?

They can last anywhere from about 10 hours to 100 hours, depending on the manufacturer, technique, surface material and torque of the saw. “If doing a significant amount of cutting, spend at least $100 to $175 on a good blade,” says Martin. “They are well worth the investment!”

Is cutting concrete difficult?

Yes. “Not only is it physically tasking work, which involves heavy equipment and materials, but it is also dirty and dangerous too,” says Walker.

Can you rent tools for cutting concrete?

Yes. You can rent concrete saw-cutting tools from most home improvement box stores, as well as tool rental companies. “The rental cost may vary from $50 to $1,000 depending on your project size and the number of tools, you may require,” says licensed contractor Jay Sanders.

How long does it take to cut concrete?

How long it takes to cut concrete depends on the length and depth of the cut, the quality of the saw and your experience level. “Smaller projects can be accomplished within a few minutes, whereas larger ones might require several hours,” says Sanders. “If you cut through a 4-inch thick concrete slab, using a professional-grade saw, it may demand approximately 45 minutes to one hour.”

Should you wear a mask when cutting concrete?

Yes, definitely. You should wear, at minimum, an N95 respirator mask, plus use other dust control methods such as water or a vacuum.

“Silica dust is a real danger, and it should be feared just as much as people do with mold or asbestos because it can cause serious health problems when not respected,” says Walker.

About the Experts

• Brandon Walker is Superintendent at ASAP Restoration in Tempe, Arizona. He has more than 20 years of experience in the industry, doing everything from running his own company and ASAP teams to all of the odd-jobs in between.
• Jeremy Martin is owner of Willow Gates Landscaping in Mohnton, Pennsylvania, which he founded in 2005. He shares his passion for the industry by teaching installer courses for retaining walls, concrete pavers, permeable pavers and advance hardscape projects, plus speaking at industry events.
• Jay Sanders is a licensed contractor based in Baltimore. He owns Maryland Contractor and Castle Dream Construction, and has been working in construction for more than a decade.