How to cut a concrete slab comes down to four things: the right saw and diamond blade, a marked and checked cutting line, the correct depth cut in controlled passes, and proper dust and water control. For most Perth jobs, such as removing a section of driveway, opening up a slab for plumbing or adding control joints, a handheld petrol demo saw fitted with a diamond blade does the work.
Concrete looks simple until you hit reinforcement, an unknown service line or a slab that behaves differently from what you expected. This guide walks you through what to check before you cut, how to choose the saw and blade, the step-by-step cutting process, and what to ask before you book concrete cutter hire in Perth.
Can You Cut a Concrete Slab Yourself?
For many residential jobs, yes. Cutting a trench line across a garage slab, removing a section of path or driveway, or adding control joints are all common DIY tasks with hired equipment. You need to be comfortable with heavy petrol tools, willing to wear full protective gear and prepared to do the groundwork before the blade touches the concrete.
Some slabs should not be cut without professional advice:
- Post-tensioned slabs. These contain tensioned steel cables. Cutting one can be extremely dangerous and can compromise the whole slab.
- Structural slabs that support walls, columns or a floor above.
- Slabs close to services you can’t locate or identify.
- Large or deep cuts that need engineering input or council approval.
If any of these apply, speak to your builder, an engineer or a licensed concrete cutting contractor first.
Also Check: Hiring Tools vs Calling a Tradie
What Equipment Do You Need to Cut a Concrete Slab?
The right saw depends on how deep and how long your cut is.
| Job | Suggested Saw | Notes |
|---|---|---|
| Short or shallow cuts, small sections | Handheld demo saw | Portable and fast, ideal for most residential work |
| Long straight cuts, driveway sections | Demo saw with a trolley | Keeps the cut straight and reduces operator fatigue |
| Control joints in fresh concrete | Early entry (soft cut) saw | Cuts shallow joints within hours of finishing the pour |
| Deep or heavily reinforced cuts | Professional wall or floor saw | Usually a job for a specialist contractor |
At Quinns Rocks Tool Hire, our concrete equipment and saws ranges include Husqvarna demo saws, a demo saw trolley and an early entry soft cut saw, so you can match the machine to your slab.
Also Check: The Difference Between Demo Saws and Concrete Saws
What Is a Demo Saw?
A demo saw is a handheld, petrol-powered cut-off saw built for fast, aggressive cuts through concrete, masonry and asphalt. It’s the most common choice for slab cutting because it’s portable and powerful.
Also Check: What Is a Demo Saw? Uses, Benefits and When to Hire One
Choosing the Right Blade
The blade matters as much as the saw. Using the wrong one makes the cut slow, rough and sometimes unsafe.
- Diamond blades are the standard for cutting cured concrete. They grind through aggregate rather than slicing it.
- Blade hardness. Harder concrete generally wears the blade more slowly but cuts slower, while softer or abrasive concrete suits a different blade grade. Tell our team what you’re cutting and they’ll match the blade.
- Reinforced concrete. Steel bar and mesh wear blades faster and need a blade rated for it.
- Blade size. A standard 14 inch (350mm) blade on a handheld demo saw typically cuts to a depth in the region of 120mm to 125mm, though exact limits depend on the saw and blade, so confirm the specification for the model you’re hiring.
Never use a damaged, cracked or glazed blade, and always check the blade is rated for the saw’s maximum RPM.
Before You Cut: Check the Slab First
Spending an hour on checks is the difference between a clean job and an expensive mistake.
1. Find Out How Thick the Slab Is
Check the plans if you have them, or measure at an exposed edge, a previous core hole or a small test drill. Cutting depth is limited by blade size, so you need to know whether one cut will do or whether you’ll need to cut from both sides.
2. Check for Reinforcement
Most slabs contain steel mesh or bar. A metal detector, a concrete scanner or ground-penetrating radar can map it. If a scan isn’t available, assume reinforcement is present and use a blade rated for it.
3. Locate Underground Services
Electrical conduit, water pipes, gas lines, communication cables and irrigation can sit inside or under a slab. Contact Before You Dig Australia before you cut, and check plans and visible entry points. If you’re unsure, don’t cut until a locator has confirmed the line.
4. Check for Post-Tensioning
If the slab is post-tensioned, or you can’t be sure, stop and get advice. Post-tensioned slabs are usually found in some commercial and larger residential builds, and cutting into a cable is a serious hazard.
5. Plan Where the Slab and Debris Will Go
Cut sections are heavy, and a section of driveway can weigh far more than you’d expect. Decide how you’ll lift, break up and remove the concrete before you start.
How to Cut a Concrete Slab: 7 Steps
- Mark your cutting line. Use chalk or a crayon and a straight edge. Mark the line clearly, and for long cuts, snap a chalk line so you can follow it.
- Set up your water and dust control. Connect the water feed for wet cutting, or arrange extraction for dry cutting. Our guide explains which suits your site.
- Set the blade depth. Decide how deep each pass will go, rather than trying to cut the full depth in one hit.
- Make a shallow scoring pass. Run the blade along the line at a shallow depth first. This sets the groove and helps stop the blade wandering.
- Cut deeper in controlled passes. Make additional passes, increasing depth each time, and let the blade do the work at a steady pace.
- Cut corners carefully. Don’t overcut past a corner, and finish corner cuts with a drill or a smaller cut where the blade can’t reach.
- Lift out and break up the section. Once cut through, lift the section out or break it up with a breaker. Our jackhammer guide explains which breaker suits the job.
Also Check: Wet Cutting vs Dry Cutting Concrete
Tips for a Straight, Clean Cut
- Keep the blade square to the surface, and avoid twisting or levering it in the cut.
- Don’t force the saw. Let the blade cut at its own speed.
- Use a trolley or guide for long runs, since freehand cuts tend to wander.
- Keep the cut line visible by clearing slurry or dust as you go.
- Take breaks. Vibration and noise add up over a full day.
Also Check: Jackhammer Hire Guide: Electric vs Petrol Breakers in Perth
Wet or Dry Cutting?
Wet cutting uses a water feed to cool the blade, cut dust at the source and extend blade life. Dry cutting is quicker to set up but produces a lot of dust and needs proper extraction. Concrete dust contains crystalline silica, which is harmful when breathed in, so wet cutting or on-tool extraction is the sensible approach for most jobs.
If you’re working indoors or near a neighbour’s property, water control and slurry cleanup need planning too. Don’t let slurry run into stormwater drains.
Cutting Control Joints in a Fresh Slab
Control joints are deliberate, shallow cuts that guide where a concrete slab cracks as it shrinks and settles. They’re commonly cut to roughly a quarter to a third of the slab thickness, and spacing depends on slab size, thickness and design, so follow your engineer’s or concreter’s plan.
Timing matters. Joints need to be cut once the concrete is firm enough not to ravel, but before shrinkage cracks form. An early entry saw is designed for exactly this, which is why it’s popular for driveways and patios.
Also Check: How to Build a Concrete Patio: Step-by-Step Guide with Tool Hire Options in Perth
Safety When Cutting Concrete
A demo saw is a powerful, fast-spinning tool, so treat it with respect.
- Wear eye protection or a face shield, hearing protection, a properly fitted P2 respirator, steel-capped boots and gloves.
- Keep bystanders, children and pets well clear, and cordon off the work area.
- Hold the saw firmly with both hands and stand to the side of the blade, never directly behind it.
- Watch for kickback, which can happen if the blade binds in the cut.
- Check your fuel, blade and guard before every start.
- Never cut with a guard removed or a damaged blade.
Concrete dust is a long-term health risk, not just a short-term irritation. Safe Work Australia has detailed information on crystalline silica and how to control exposure.
Common Mistakes When Cutting a Concrete Slab
- Skipping the service check. Cutting into a pipe or cable is expensive and dangerous.
- Cutting full depth in one pass. It overloads the blade and makes the saw hard to control.
- Using the wrong blade. A blade not rated for concrete or reinforcement wears fast and cuts poorly.
- Not planning slab removal. Cut sections are heavy and awkward.
- Cutting dry without protection. Silica dust is a real hazard.
- Cutting a structural or post-tensioned slab without advice. This is the one that can’t be fixed after the fact.
How Long Does It Take to Cut a Concrete Slab?
A short cut through a residential slab might take an hour or two once you’re set up, while a long driveway section, multiple joints or a heavily reinforced slab can take a full day or more. Allow time for setup, blade changes, slurry cleanup and removal. Quinns Rocks Tool Hire offers hire periods from 24 hours through to long-term.
Also Check: Daily vs Weekly Hire
What to Check Before You Book Concrete Cutter Hire
Having these details ready helps our team recommend the right saw and blade:
- Slab thickness and whether it’s reinforced
- Cut length and depth
- Whether you need a demo saw, a trolley or an early entry saw
- Wet or dry cutting, and access to water
- Indoor or outdoor job
- Whether you’ll also need a breaker to lift out the section
- How you’ll transport and refuel the saw
Concrete Cutter Hire vs Hiring a Contractor
For short cuts and straightforward residential work, hiring a saw and doing it yourself can cost far less than a contractor. For structural slabs, deep or very long cuts, post-tensioned slabs and anything near services you can’t locate, a licensed concrete cutting contractor is the safer choice.
For Alkimos and Butler jobs, you can also read our local guide to concrete grinder and saw hire.
Also Check: Concrete Grinder and Saw Hire in Alkimos and Butler
Why Choose Quinns Rocks Tool Hire for Concrete Cutter Hire in Perth
Quinns Rocks Tool Hire has supported Perth’s northern suburbs with reliable, well-maintained equipment for over 19 years, including Quinns Rocks, Mindarie, Alkimos, Butler and Clarkson. Our team can help you choose the right saw and blade for your slab and walk you through safe operation at handover.
Browse our full range of concrete equipment, or head to our homepage to see everything else we hire out.
Frequently Asked Questions
1. What is the best saw to cut a concrete slab?
For most residential jobs, a petrol demo saw with a diamond blade is the best all-rounder. Long cuts benefit from a trolley, and fresh concrete joints suit an early entry saw.
2. How deep can a demo saw cut?
A standard 14 inch (350mm) blade typically cuts to roughly 120mm to 125mm, though this depends on the saw and blade. Thicker slabs may need cuts from both sides or a different machine.
3. Can I cut a concrete slab with an angle grinder?
An angle grinder with a diamond blade can handle short, shallow cuts, but it’s limited in depth and slow for long runs. A demo saw is far better for slab work.
4. Is it better to cut concrete wet or dry?
Wet cutting is generally better because it controls dust, cools the blade and extends blade life. Dry cutting needs proper dust extraction and respiratory protection.
5. How do I know if my slab is post-tensioned?
Check building plans and ask your builder. If you can’t be sure, don’t cut until a professional has confirmed what’s inside the slab.
6. Do I need to check for pipes and cables before cutting?
Yes. Contact Before You Dig Australia and check plans before cutting. Never cut near services you can’t identify.
7. Where can I find concrete cutter hire near me in Quinns Rocks?
Quinns Rocks Tool Hire is based in Quinns Rocks and services Perth’s northern suburbs. Contact our team to check saw availability for your dates.
Final Thoughts
Cutting a concrete slab is straightforward when you prepare properly: check the slab, choose the right saw and blade, cut in controlled passes and control the dust. Skip the checks and the same job can turn into a safety hazard or a costly repair.
Ready to book? Get in touch through our contact page and our team will help you choose the right concrete cutter for your project.
