A worker is only as good as his or her tools. It’s a cliché, but only because it’s true. The adage might have been coined with concrete cutting in mind. Choosing the proper concrete saw based on your application is critical. Concrete’s physical characteristics can turn an expensive concrete saw blade into sawdust if it is used in an operation for which it is unsuited.
Concrete Cutting Tips
Whether you use a cutoff saw, walk-behind, block saw, or other variety, there are a number of best practices to observe to achieve the best results and make operation as safe as possible:
- Cut on Time – In almost every case, after concrete fully cures, it’s too late to cut effectively. It is prone to fracture. On the other hand, concrete that is not fully dry presents its own set of problems. Like Goldilocks, you need to cut concrete when the timing is just right: After it has cured, but before it has hardened. The cut will be smoother and create less dust.
- Keep it Clean – Speaking of dust, make sure you don’t inhale it. Wear an approved respirator attach a dust shroud, and seal off areas in which concrete saws will be in use.
- Stay on the Straight and Narrow – For straight cuts, mark the cut path with a chalk line of, if water from wet cutting washes away the chalk, a wax pencil. Clamp a straightedge to the outside of the line as a guide for the saw. Keep a firm grip on the saw at all times to ensure safety and control.
- Don’t Lose Your Cool – Patience is a virtue when using concrete saws. Allowing the blade to do the work alleviates muscle fatigue and prevents handheld saws from bucking. Don’t force the saw through the concrete; simply guide it along the cut path. Cutting thick concrete with a series of shallow cuts will improve accuracy and keep the saw from overheating. Make several passes, cutting a half-inch to an inch deeper each time through.
Saw Choice
Concrete saws come in a variety of styles, each with its own strengths and weaknesses. Picking the right saw is a function of three considerations.
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The Application
As discussed, each type of concrete saw is built for specific cutting jobs:
- Walk-Behind Saws – These large, cart-mounted saws work on horizontal slabs such as parking lots, home foundations and patios, and airport runways. Use them when long, straight cuts are needed; their heft helps keep the blades in line.
- Cutoff Saws – Gas-powered hand-held cutoff saws can cut through brick and metal, as well as concrete. Cutoff saws’ portability and maneuverability make them the tool of choice for cutting windows and other openings in precast concrete up to five inches thick.
- Chainsaws – Resembling chainsaws made for cutting wood, concrete chainsaws are the go-to tool for cuts deeper than the 5 inches a cutoff saw can deliver. They work best when cutting deep, narrow openings. Their strengths also including cutting sharp angles and square corners not possible with circular blades.
- Early-Entry Saws – Primarily used to cut crack-control joints in uncured concrete, early-entry saws feature plates that exert downward pressure on the cutting surface while blades slice the concrete in an up-cutting orientation to relieve stress on green-zone concrete before it can crack during curing and hardening.
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The Blade
Concrete is hard, so concrete saws need hard-edged blades to cut it. And since nothing is harder than diamonds, diamond blades are the preferred method, no matter what type of saw you’re using. With that issue decided, there still are several decisions to be made to determine your best blade option:
- Compatibility – Choose blades whose diameter and cutting depth are compatible with the saw’s specifications and that conform to the saw’s horsepower and RPMs. Operating a blade with a too-powerful saw risks injury and malfunction, while using a blade at a slower-than-recommended speed will compromise performance and reduce its lifespan.
- Specialty – Blades designed for cutting green concrete are almost always made for use with early-entry saws. Likewise, while some dry-cutting blades can be use in wet-sawing applications, the reverse is never true. Wet-cutting blades should never be used in dry-cutting operations.
- Material – Diamond blades work by embedding diamond chips and dust in a matrix that adheres them to the blade. As cutting friction wears away the matrix, new, sharp diamonds are exposed. The softer the matrix, the faster this erosion and diamond replenishment occurs. So, harder matrices use each diamond layer for longer periods, making them the right choice for softer concrete. Softer matrices are the best option for harder concretes (those made of quartz aggregate, for example), because it dulls the diamonds more quickly, so they should be replaced more often.
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The Niche
Some concrete saws are manufactured to solve specific issues or meet the needs of particular industry niches. For instance, Husqvarna makes two saws that address issues general concrete cutters often encounter:
- Husqvarna K 760 Cut-n-Break – This saw trims hours of the time required to cut through thick concrete walls. Its twin blades cut a core into the concrete about three inches deep. A companion tool is used to break off the core, clearing the path for another three-inch cut. Repeat the process until you’ve cut through the slab.
- Husqvarna K 6500 Ring – This electric saw combines deeper cutting action with less vibration to allow longer operation for extended projects. Capable of cutting up to 10 inches deep in a single pass—double the depth of most competitors—this powerful electric saw incorporates great balance and light weight for excellent user comfort.
Pro Group carries a complete line of concrete saws for every application. Contact our experienced team for help selecting the saw and blade that will work best for your project.
