Concrete cutters use core drilling to drill a perfectly round hole into an area of concrete. This is commonly for things such as to ventilate a furnace, add in plumbing, or repair electrical work. Holes vary in size depending on what you need but are typically around a few inches in diameter. These cuts are called Construction Cuts (also called Construction joints, Expansion Cuts, or Expansion joints) and must be correctly positioned and done within 24 hours of the concrete being poured, otherwise there is a significant risk of concrete cracking (unless other jointing methods are used).Saw cuts are a used to create control joints in concrete, which help control where cracking occurs due to shrinkage. The cuts should be made at a predetermined spacing and only after the concrete has obtained sufficient strength but before internal cracking begins. Therefore, the timing of saw cuts is critical.