Concrete Saws – What You Need To Know

What Is a Concrete Saw?

Concrete saws—also known as cutoff saws, road saws or demolition saws—are power tools with diamond‑coated blades designed to cut through concrete, masonry, brick and asphalt. They come in various configurations to suit different tasks. The blade may be a circular disc, chain or ring, and may be mounted on a handheld body, push cart or track system. Cutting concrete produces significant dust and noise, so many saws incorporate water delivery systems or connect to vacuums to minimise hazards.

Concrete saw (operational)” by Kevin Payravi is licensed under CC BY‑SA 4.0 and can be found at https://commons.wikimedia.org/wiki/File:Concrete_saw_(operational).jpg

Types of Concrete Saws and Their Uses

1. Concrete chain saws: These resemble woodworking chain saws but use specially designed diamond chains. They excel at cutting small openings, tight corners or irregular shapes. A chain saw can plunge cut through a wall or create controlled openings for windows, doorways or plumbing penetrations. Water supply is integral to keep the chain cool and reduce dust.
2. Circular saws (handheld cutoff saws): These handheld units feature spinning blades (typically 300–400 mm diameter) and are versatile for general cutting. When fitted with diamond or abrasive blades, they cut through concrete blocks, pavers and small slabs. Adjustments to depth and angle allow for precise cuts. They are ideal for cutting pavers to fit around a garden bed or trimming off a misaligned slab edge.
3. Walk‑behind saws: Also called push saws or floor saws, these larger units are mounted on carts with adjustable blades. They are used for cutting expansion joints, removing damaged sections of driveway, trenching for plumbing or electrical conduits and creating decorative grooves. The operator walks behind the saw, guiding it along a marked line. Self‑propelled versions reduce operator fatigue.
4. Wall saws: These specialist saws have a track‑mounted blade that travels along a wall or vertical surface. They are used for precise cuts in vertical concrete such as cutting openings for doors, windows or air‑conditioning units. They usually require professional installation and are less common for DIY projects but may be hired with an operator.
5. Ring saws: Featuring a blade that runs around a ring rather than through a centre arbor, ring saws can cut deeper than circular saws of the same diameter. They are good for cutting deep openings in walls or slabs without over‑cutting the corners.
6. Road saws: Larger petrol or diesel‑powered units used for cutting asphalt and concrete on roads, driveways or large slabs. Unless you are replacing a section of driveway, these are more equipment than most homeowners need.

What to Look for When Hiring

1. Cutting depth required: Determine the thickness of the slab or wall. For a driveway slab typically 100 mm thick, a handheld circular saw with a 300–350 mm blade may suffice. For deeper cuts (e.g., 150 mm plus), a ring saw or walk‑behind saw might be necessary.
2. Power source: Electric saws are quieter and produce no fumes, but petrol saws are more powerful and portable. Ensure there is adequate ventilation if using petrol saws in garages. Battery‑powered saws exist but usually have limited run time for heavy cutting.
3. Wet versus dry cutting: Wet cutting supplies water to the blade to reduce dust and cool the blade. Choose a saw with a water feed if possible. Dry cutting must be done with a dust extraction system and is best avoided for DIY jobs.
4. Blade type: Diamond blades come in various formulations for cutting different materials. The hire company should supply the correct blade for concrete, asphalt or brick. You may need to pay for blade wear, so ask about wear charges.
5. Vibration and ergonomics: Cutting concrete can be physically demanding. Look for saws with anti‑vibration handles, good balance and adjustable depth levers. Self‑propelled models reduce the push effort.
6. Safety features: Check for blade guards, water connection points and reliable shut‑off switches. Operators must wear full PPE including goggles, ear defenders, gloves, boots and respiratory protection.

Tips for Using a Concrete Saw

• Mark your cut clearly: Use chalk or a straight edge to mark the cut line. Double‑check measurements to avoid mistakes, as cutting errors are hard to fix.
• Set up the work area: Ensure there is adequate space to manoeuvre the saw and that the slab is free of obstacles. Remove hoses or cords from the cutting path.
• Prepare the saw: Install the correct blade, tighten it properly and check that the water supply (if wet cutting) is working. If using a walk‑behind saw, adjust the blade to the correct depth before starting.
• Use proper body positioning: Stand with a stable stance and maintain a firm grip. Let the saw’s weight and the blade do the cutting; do not force it. Maintain a steady feed rate to avoid overheating the blade or stalling the motor.
• Control dust and slurry: Water will create slurry, so have a wet vacuum or shovel and bucket ready to collect it. For dry cutting, attach a vacuum to capture dust. Avoid breathing dust from concrete cutting as it contains silica.
• Stop and inspect: Periodically stop to check the cut, ensure the blade is not overheating and adjust as necessary. Allow the blade to spin freely for a minute after cutting to help it cool.
• Turn off and secure: Once finished, turn off the saw, allow the blade to stop completely, disconnect power or fuel and set the saw down. Clean up slurry or dust, and store the saw safely until returned.

Example Scenario

You need to install a new drainage pipe across your driveway to prevent pooling of water during heavy rain. The driveway is 100 mm thick concrete. You hire a walk‑behind petrol saw with a 350 mm diamond blade and a water hose attachment. After marking the trench line, you set the blade depth to 50 mm and make a first pass. You then increase the depth to 100 mm and make a second pass to cut through the slab completely. By controlling the saw’s speed and using water for cooling, you achieve a straight, clean cut. Once the section is removed and the pipe laid, you pour a new concrete section to restore the driveway.

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