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How to cut concrete blocks with circular saw

Concrete is considered the strongest building material. It can be used in many different types of construction projects such as foundations, flooring and even entire buildings. However, to be used for such purposes it must first be cut into smaller pieces so that they can be handled easily. Here we will discuss how to cut concrete blocks with circular saw.

Fortunately, cutting concrete is easy with the help of a circular saw or miter saw and some basic knowledge about the material.

How to cut concrete blocks with circular saw

This is how you cut concrete blocks into smaller pieces. A circular saw with a carbide blade will work best.
Step 1: Select your block. Inspect it closely to see if there are any cracks. Block with cracks will break along the crack as you’re cutting it. Find a block that’s solid and place it on level ground. If there is no flat area, then stack up some scrap wood or bricks to make a stable working platform.
Step 2: Select your saw blade based on the material you are going to cut. Be sure that you use a blade suitable for cutting concrete and not an ordinary wood-cutting blade. A carbide-tipped blade will cut through the block fastest and make the smoothest cut, but they are also more expensive than most other blades.
Step 3: Connect your saw to a heavy extension cord and plug it in. Set the blade depth to the thickness of the block you are going to cut. Start with a shallow cut and deepen it from there. Use a carpenter’s measuring tape to measure the blade distance from the ground. Keep in mind that your extension cord may be too short to power your saw, which will prevent further cutting if you don’t have an adequate supply.
Step 4: Secure your saw in place by wedging it against the base of the block or with heavy scrap wood or bricks to hold it in place. Make sure that the surface you are cutting is flat and stable so there won’t be any vibration while cutting, which can cause inaccuracy.
Step 5: Switch the saw on and begin cutting the concrete block. Apply moderate downward pressure on the blade to prevent it from jumping around or downward jerks that will cause inaccuracy. Guide the saw with your hands and do not let it cut too fast for this is what causes vibration, which can interrupt your work progress.
Step 6: Continue cutting until you completely pass through all four sides of the block’s surface. If you are not sure about your blade position, then cut to one side only until you are through, then turn it around and cut once more from the other side. Verify that you have completely severed all four surfaces before removing the saw from the block.
Step 7: Clean up debris by brushing them away with a broom. Sweep up any particles left behind and discard them in an appropriate container.
Step 8: Remove the block from the platform you used to secure it in place, or take off any scrap wood or bricks that you used to hold your saw in place while cutting. Make sure that there is nothing left on the surface except for dust before you pick up the block.
Step 9: Check the cut edge of your block. If it is rough and contains sharp or jagged edges, then use a grinder and large round grinding disc to smooth them out. Grinding discs made for concrete surfaces work best but must be used with caution because they can damage your saw’s blade if it comes in contact with it.
Step 10: Place the block on a stack of scrap wood and cut it into smaller pieces. Measure these pieces to make sure that they are uniform in dimensions and weight before you begin stacking them for later use.

Tips and Instructions about cutting concrete blocks

  • Before you use your circular saw, be sure that it is well-maintained and always kept sharp.
  • Inspect the blade regularly to see if any cracks or chips have developed on its surface. Replace it immediately if such problems are discovered.
  • Be mindful of sparks that might fly off from the blade as you make cuts because these can cause small fires if they land in the wrong places.
  • Use a grinder to smooth out rough edges in your cut and to even out uneven spots that might be there, but do not use it for heavy grinding or shaping work.
  • Use safety goggles and ear protection as recommended by the tool manufacturer. Wear long sleeves and pants, as well as work boots for foot protection.

FAQs

Q. Can I use a regular circular saw blade for cutting through concrete?

A. No, not unless it’s at least 80-grit carbide. An ordinary blade will heat up and crack from the extreme material difference between wood and concrete.

Q. What is the best saw for cutting through an upright concrete block?

A. A cordless circular saw with a 90- or 100-grit blade will work just fine, but you would need to take frequent breaks and be mindful of overheating issues during long jobs. Otherwise, you might need 1/2″ masonry bit and a hammer drill.

Q. Is there anything I can do to reduce vibration during cutting?

A. Yes, but only to a certain extent. You can place your saw on something such as scrap plywood or bricks so it doesn’t directly contact the concrete surface you’re cutting through and lower the blade into the concrete by about 1/8″ using either shims or by pressing down on the saw’s shoe.

Q. Is it safe to keep my circular saw outside without protection?

A. You can store your circular saw outside if you wish but do so with caution because its metal casing will weather over time, which causes oxidation and rusting that can eventually damage your saw’s internal parts. Better to place it inside a garage or shed where the temperature and humidity is well-controlled.

Q. Why does my circular saw wobble when I’m cutting?

A. This could be caused by either dull blades or too much vibration from the tool but you can fix this easily by replacing the blade with a new one.

Conclusion

As you can see, cutting through concrete blocks is not as difficult or complicated as it might sound. All you need are the right tools, patience and the willingness to follow the above-mentioned steps closely and you are all done with How to cut concrete blocks with circular saw. Pay close attention to the safety concerns and follow all product instructions accordingly. Good luck and happy cutting!

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