How To: Cut Through Concrete

The reasons for cutting concrete

You may want to cut through your sidewalk pavement, solid countertop, outdoor patio or BBQ wall.

Following correct safety precautions, you can cut through concrete using a diamond blade.

For cutting through slabs with a thickness of six inches or more, it would best to leave the job to a professional. A depth below this, which usually includes most walls, sidewalks and patios can be cut by anyone handy with DIY at home.

The most essential tool is the diamond blade. While these blades do the job well, they quickly wear out, and so may need to be replaced a number of times throughout a project.

man cutting concrete

Safety note: Abrasive blades like the diamond blade may lead you to effectively “force” the saw. This is a dangerous action which could result in you losing control and sustaining a potentially life-threatening cut. So don’t risk it, purchase a high quality blade.

Cutting concrete with diamond blades

Stage 1

Choose the type of blade based on the job: dry-cutting diamond blade or wet-cutting diamond blade.

Stage 2

Prepare your workspace.

Stage 3

Where you need to cut, mark it either using a chalk line or chalk. Ideally, run water on the concrete to minimise dust.

Stage 4

Adhere to all personal safety precautions: guards for your shins, pads for your knees, steel-toe capped boots, in addition to protective eye wear and ear plugs. A correctly fitted filtration mask is a must-have! 

Stage 5

Where possible, allow some water to trickle over the line you wish to cut.

Stage 6

Beginning at either end of your cut, place a guide board (any 1 inch deep scrap piece of wood) along the outer chalk line.

Stage 7

With the saw completely off, set the blade depth by the depth lever so it will cut half of an inch deep. This ensures that you control the saw better for the shallow cuts.

Switch on the saw and set it at the lowest RPM setting, beginning your initial cut along the chalk guide line.

Cut for 30 – 45 seconds.

Stage 8

Remove your saw from the cut line, letting it freely spin; this provides the opportunity to spit out dust clogging up the saw. Alternate between 30 – 45 seconds of cutting and cooling off until you finish the project.

Dust will gather during cutting, despite you trying to keep your concrete wet. Take regular breaks to clear out dust.

Stage 9

For a deeper cut, switch off the saw and increase your blade depth by half-inch increments with the saw’s depth lever. Resume your cut by following the technique outlined above in Step 7 and 8.

And Finally…

Once the concrete around the cut line is knocked away, go back over it and gently tap away any excess concrete for a much cleaner line. If you’ll pour new concrete to replace a cracked concrete driveway or patio slab however, leave the edge jagged and jutting out a bit, giving the new concrete something to bond with.