In a word, yes. Many contractors shy away from step cutting when cutting through a slab in preparation for breaking and removal. The typical excuses run from not wanting to change saw blades to time constraints to basically not thinking it makes any difference.

However, it really pays to do the job right. I once worked for an old contractor when I was a young man and he would often recite: “be the jobs, big or small, do it right or not at all” I grew quite tired of hearing his rhyme but it stuck with me because he had a good point!

First of all, let me explain the concept of step cutting. Let’s say we have a ten inch thick slab to cut and remove. The top is two inches of asphalt over eight inches of concrete with number five rebar mats throughout.

Our first cut will be with a fourteen inch by quarter inch thick Asphalt Blade. An asphalt blade has a hard bond mix and undercut protection. In order to cut one slot one quarter inch wide, we sometimes use a blade that thick (.250”) or we often use two blades mounted side by side on the spindle of standard thickness (.125” each)

With the initial slot open and the highly abrasive asphalt cleared out of the way, we make the second cut with a twenty inch concrete blade with a thickness slightly lower than our initial slot (.187”). The advantage of using a narrower diamond blade on each successive cut is that it doesn’t have to re-cut the sides of the previous cut. In this case we use a concrete blade and avoid the asphalt. The twenty inch concrete blade cuts a depth of seven and one half inches. Depending on the hardness of the concrete we take this depth in one or two passes. Always be sure to match the bond on your saw blade to the Aggregate of your concrete.

Last, we need to use a concrete blade of at least twenty six inches in diameter to cut the rest of the way through the slab. The thickness can be either the same the previous cut (.187”) or thinner (.175). If you decide to go with a larger blade, like a thirty six inch one, just be mindful not to drop the blade too deeply under the slab. Even though the temptation is to cut way under the slab in order to account for variations in depth, it results in a tremendous waste of a very expensive diamond blade. Because the sub grade can be either sand or rock, cutting through it wears the diamond blade but actually accomplishes nothing.

The greatest advantage to step cutting is through reduced blade wear. The larges blades are significantly more expensive than the smaller blades. In the long run using your blades is this manner reduces cost. Our company actually cuts concrete every single day, so we know what we are talking about. Try step cutting for yourself on your next big job and you will never go back to the single blade approach again.