How To Cut A Thick Concrete Slab

Cutting thick concrete slabs neatly and with high precision is not an easy task. In fact, cutting any kind of concrete is hard.

You need to have the knowledge, expertise, and experience to be able to do a decent job. It also helps if you have excellent hand-eye coordination and strength. 

Although concrete cutting is best left to the professionals due to the dangerous and vigorous nature of the job, in this article, we will take a look at what is required to cut through a thick slab of concrete.

What Is Needed For Cutting Concrete?

• For concrete slabs under 10cms, you will need a circular saw with at least seven inches blade, 15 amps minimum. 
• For concrete slabs thicker than 10cms, you will need at least a 14-inch blade.
• Markers like chalk or bright coloured crayons or pens.
• Measuring tools
• Personal Protective Equipment

Things To Do Before You Start Cutting

• Clear the area from clutter, obstacles, and anything that can cause harm or accidents.
• Make sure that other people within the area stay clear from your workspace.
• If you are using gas or fuel-powered concrete saw, make sure the area is free from anything that can spark or easily combust.
• If you are using an electric wet concrete saw, make sure your cords, extension lines, etc are waterproof. 
• Keep your electrical cords organised to avoid tripping yourself and other people involved in the process.
• Measure properly for accuracy.
• Make clear marking on the concrete slabs.
• Consult a structural engineer to make sure that your measurements are correct.
• Always wear protective gear.
• Follow safety protocols.
• Check the concrete saw. Make sure it is in perfect running condition.
• Ground fault circuit interrupter-protected extension cord.

Where To Cut?

Depending on the thickness of the concrete slab, the cuts must be spaced between 24 to 36 times the slab thickness.

And depending on the amount of reinforcement the concrete slab has, control joint spacing is normally set at 3 to 5 metres apart. You can reduce the cut spacing for high-shrinkage concrete. 

A good rule of thumb is cutting the concrete slab a quarter or a third of the slab thickness. So for a 25cm concrete slab, you cut 5 to 6cms. 

How To Cut?

1. Layout the joints to be cut. Clear your workspace. Get rid of any clutter and debris that can hinder the smooth operation of the concrete saw or cause any accidents.
2. Mark properly using bright-coloured chalk or pens. Make the lines as thick as possible. Make sure that you use a good marker so the marks will not wash away especially when you are using a wet saw.
3. If you are using a wet saw, check and make sure the water runs all the way down to the blade. A wet saw with a diamond blade is highly recommended for a smoother and safer job.
4. Position the blade against the slab and start following the marked areas. Take your time and go easy on the blade.
5. Do not push the blade too hard, just guide the blade and let it do its job.
6. Use a guide board and start at one end of the cutting area, whichever is easiest for you. 
7. When done, remove the saw from the concrete and let it spin freely for a minute to spit out any dust or particles and to cool the blade down. Repeat the process until all cuts are done.
8. Allow 30 to 40 seconds in between cuts to let the blade cool down. 
9. Unplug the concrete saw when done. Clean it and tuck away all tools. 
10. Clean the area and get rid of the dust and water. 

Safety Equipment

Cutting concrete is not an easy job. You put yourself in harm’s way every time you operate a concrete saw. Protect yourself at all times.

Losing a toe or a finger is a real danger that goes with the job. Educate yourself in proper handling and operation of concrete saws. Wear the required personal protection equipment or PPEs.

Safety first, at all times. Better safe than sorry!

Important cutting tips:

• Do not push the blade too hard.
• Do not twist the blade.
• Do not let the blade spin in the cut.
• Use blades with soft metal segment bonds when cutting concrete with heavy rebar.
• Do a safety check on your concrete saws before and after using.

Cutting concrete is a job for trained professionals so it’s safer to leave it to the experts. That’s where Megasaw comes into the picture.

We service residential and commercials projects, delivering only the best concrete cutting and drilling solutions for our clients.

If you are looking for a specialist concrete cutting company who uses only the best practices to get the job done right, then please call us at Megasaw on 1300 920 419 or contact us through our website.