How to Cut Asphalt

Using a Circular Saw and Diamond Blade

Sweep the asphalt with a broom to remove any loose debris. Thoroughly clear the area of asphalt where you plan to cut by sweeping any loose chunks of asphalt or other debris off to the side. This will ensure the area is clear and safe for cutting. Small chunks of asphalt or rocks that the blade of your saw runs into could fly up dangerously to the side or back at you and cause injury, so it’s important to make sure the area is totally clear. A circular saw equipped with a diamond blade is ideal for making long straight cuts in asphalt.

Mark the lines you want to cut with chalk. Use a chalk line to make long straight lines, such as for the entire length of an asphalt driveway. Use a piece of chalk and a straight edge if you want to make shorter lines, such as around a piece of damaged asphalt that you want to cut out. A chalk line is a retractable string line covered in chalk that you stretch out in a straight line just above the ground, then lift up and let it snap back down against the ground to leave a chalk line.

Put a diamond blade into a circular saw. Diamond blades are strong enough to cut into asphalt, whereas regular saw blades will get damaged trying to cut such hard material. Make sure your circular saw is powered off and unplugged, then use a wrench to loosen the nut that holds the blade in place and swap it out for a diamond blade. You can get a diamond blade at a home improvement center or power tool supply shop. If you don’t have a circular saw, you can rent one from there as well and have the store fit it with a diamond blade for you.

Turn on your circular saw and bring the blade up to full speed. Plug the saw in and hold the power trigger down until the blade is spinning at full speed. This will make it easier to plunge the blade into the asphalt to start the cut.Tip: A regular circular saw with a diamond blade is sufficient to cut into asphalt up to about 4 in (10 cm) deep. For anything deeper, you can use the same process with a walk-behind circular saw. You can rent these types of saws at power tool supply stores. Make sure to wear protective eyewear, a facemask, and earplugs when operating the circular saw. You can also wear work gloves if you want for added protection.

Sink the blade of the saw into one end of your cut line slowly. Plunge the diamond blade down into the asphalt. Keep pushing down slowly until it has sunk all the way through the asphalt before you start moving it along the cut. You’ll know the blade is through the asphalt when you feel less resistance.

Push the blade along the cut line slowly till you reach the end. Use both hands to guide the saw along the chalk line slowly. Lift the saw up and out of the concrete when you reach the end and release the power button to stop the saw. Repeat the process for each cut line you made if you have more than one.

Lift out the chunks of the asphalt that you cut away with a shovel. Insert the tip of the shovel into the cut line and under the asphalt that you want to remove. Use the shovel like a lever to pry up the asphalt and discard it. If the sections of asphalt you need to remove are particularly big, you can use a sledgehammer to break them up before lifting them away with a shovel.

Cutting with an Electric Chipping Hammer

Use a broom to sweep debris off the asphalt. Clear away loose dirt and pieces of asphalt or gravel from the space you plan to work in. Sweep it off to the side so you can easily mark your cut lines and make your cuts. Using an electric chipping hammer is a good method of cutting asphalt when you need to make a series of shorter straight cuts or cuts that aren’t straight. You can still use this method for long straight cuts as well if you prefer.

Draw your cut lines with chalk. Mark the lines you want to cut using a piece of chalk or a chalk line. Use a piece of chalk for small straight cuts or non-linear cuts, and use a chalk line for long straight cuts. For short straight lines, you can use a piece of chalk with a straight edge. For non-linear cut lines, you can freehand the lines with a piece of chalk or use some kind of template to trace around.

Fit an electric chipping hammer with a chisel blade. Use a narrow chisel blade for non-linear cuts or short precise lines, and a wide chisel blade work for longer straight lines. Insert the flat-ended part of the bit into the bottom of the chipping hammer and turn the locking mechanism (usually a nut or key next to where you insert the blade) to lock it in place.Tip: You can usually rent a chipping hammer from a power tool supply store or home improvement center if you don’t own or want to buy one. For example, if you are cutting out a circular section of asphalt, you would want a fairly narrow chisel blade so that you can make the cut as rounded as possible. An electric chipping hammer is basically a smaller version of a jackhammer. Put on protective eyewear, a facemask, and earplugs before you operate the chipping hammer. Gloves are optional but provide your hands with protection from flying bits of asphalt.

Place the tip of the chisel blade against one end of the cut line and turn it on. Hold the electric chipping hammer with both hands, hold it steady with the blade against the line, and let the blade do the work. The tip of the chisel blade will move in an up and down motion, sinking deeper and deeper into the asphalt to cut it apart. You will know that you have cut all the way through the asphalt if you feel the tip of the chisel blade going into the ground under it. For instance, if the ground underneath is dirt, you will feel much less resistance.

Move the chisel blade along the entire length of the cut line to the opposite end. Continue holding the chipping hammer with both hands. Pause the chipping hammer, lift it up, and move it over to the next section of the line once you have cut through the part you are working on. Work your way along the whole line and turn off the chipping hammer when you are done cutting away the asphalt you need to. If you want, you can do one entire light pass over your lines with the chipping hammer to create a groove to follow, then go back over the groove and cut all the way through the asphalt.

Pry up the asphalt chunks you chipped away with a shovel. Insert the tip of the shovel underneath the asphalt chunks you cut away. Use the shovel as a lever to pry them up and lift them away. Use the electric chipping hammer like a jackhammer to break up any big chunks that are too heavy to lift away with the shovel.