How to cut concrete blocks with circular saw

Cutting concrete blocks with a circular saw can be easy or challenging depending on your experience.

In this article, we are targeting to help those who are cutting concrete with little or no experience at all, so read on to learn how to cut concrete blocks with a concrete saw.

Types of concrete blades for circular saw

  • Abrasive Corundum Masonry Blades (they are only ideal for making a few shallow cuts)

These are the most affordable concrete cutting blades. You can also use them to cut asphalt and stucco.

Some of the major drawbacks with Abrasive Corundum Masonry Blades is that they are slow and they also make shallow cuts. And, they will also wear out quickly.

To show you why this is a major drawback, a 7” diameter blade will be at 6.5” after cutting only 1-2 feet line. This means that you will spend a lot of time adjusting your compound miter saw in order to expose more blade.

Again, these the abrasive corundum blades get so hot to a point of glowing, they smell, and they also make plumes of fine dust.

  • Diamond blades for circular saw

Diamond blades are expensive but totally worth it especially for people who want to cut concrete blocks fast or if you are cutting many blocks.

Generally, these blades perimeter is bonded with a diamond/metal. And, unlike the Abrasive Corundum Masonry Blades where you have to stop and adjust the saw to expose more blade when it wears away from cutting, this diamond/metal composite wears away slowly while revealing fresh diamond cutting edges.

The reason why it’s more economical to just purchase diamond blades despite their high price is that at the long run, you will have used dozens of the Abrasive Corundum Masonry Blades at the end of your project.

Diamond blades types:

When looking for diamond circular saw blades you will come across two categories: the Dry-cutting diamond blades, and the wet-cutting diamond blades, hence terms like “concrete block wet saw.”

  • Wet-cutting diamond blades for circular saw

There are a few advantages of using wet diamond blades when cutting concrete blocks with a circular saw.

First, the water will help lubricate the blades for easier cutting and also keep it cool because they tend to get hot with every cut.

Second, it’s the most effective option for keeping the dust down as you cut concrete blocks.

Third, wet diamond blades cut the cleanest and fastest. Thus, if you have a huge workload and you want clean cuts, buy the wet diamond blades for circular saws.

Lastly, it’s worth noting that wet-cutting diamond blades will either have smooth and continuous perimeter or just a teeth perimeter.

  • Dry-cutting diamond blades for circular saw

 These might be dangerous to use indoors as they create a lot of dust as you cut the concrete blocks. However, you are in a well-ventilated area and have the necessary protection, you will get your work done quickly with great outcome.

Again, to avoid overheating your blade when using dry-cutting diamond blades, make deeper cuts gradually.

Lastly, the dry diamond blades have toothed or serrated rim that not only helps keep the blade cool, but also helps eject waste.

Note 1: if your diamond blades stop cutting, check if the material is hard enough since the material should be hard enough to wear away their metal composite and expose the diamond edges as they are the ones that do the cutting.

Note 2: you can use a dry-cutting diamond blade without or with water, but you must always use a wet-cutting diamond blade with water.

How to cut concrete blocks with circular saw

What you will need when cutting concrete blocks with a circular saw:

  • A circular saw
  • A concrete block cutting blade for circular saw (preferably a diamond circular saw blade, wet or dry)
  • A chalk

Step 1: Mark where you want the cut on the concrete block. If it’s a huge block, mark it all around because you can only cut 2.5 inches deep when using a 7.25 inches circular saw.

Step 2: support your concrete block on a stable surface and ensure that you have enough ventilation since there might be some dust as you cut through.

  • Note: cutting concrete blocks indoors is not advisable because you might fill your air conditioning system with dust.

Step 3: Wear your protective equipment such as dust mask, gloves, eye protection, and ear protection.

  • Note: if you breathe any dust when cutting concrete blocks or any other masonry cutting, you will be risking yourself to contact a very serious condition called silicosis which is caused by airborne silica particles.

Step 4: Begin cutting the concrete block slowly but steadily without forcing the blade. You can cut partial depths at a time as this will be easier on your saw, but it might take longer.

  • Tip: since there will be dust once you start cutting, your chalk mark on the block might be covered before you go all around, so you can begin by cutting a shallow groove.

But, to keep the dust under control, have another person pour a string of water on the block as you cut. This will not only reduce the dust, but also help cool the blade.

As you cut, turn your concrete block to ensure that you have cut each side while also ensuring that the whole block is parted. If for whatever reason you’re unable to part the block with your circular saw, just grab a mason’s chisel and finish it through.

Final words

If you have been searching for some concrete cutting tips or how to cut concrete with a concrete saw, we hope that this article will be of great help.

The secrete for cutting concrete blocks with circular saw is to get all the right tools first while also focusing on your safety. Your choice of concrete block cutter will determine the outcome and also how fast the whole cutting process will be. Good luck!

Watch the video below to learn a thing or two about circular saw safety. Please do not start operating your tool if doubt.

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