Cutting through concrete is not as simple as it might look; concrete can easily crack and break, crumble into powder, or otherwise get damaged when being cut or drilled. It also creates a tremendous amount of dust that many amateurs are not prepared for when they decide to cut through their own basement floor or other concrete surface. If you have some concrete cutting to do yourself, note a few things to remember so you avoid some very common, and often quite costly, mistakes.
Stop if you hit something solid
You may not realise that many concrete surfaces are set with rebar or other steel forms inside, to keep the concrete strong and allow it to set properly. If you're cutting or drilling concrete and feel any resistance or know you've hit something solid, don't assume it's just a very compacted area of the concrete itself. You may be hitting this metal form and, if you keep cutting, you could easily damage or even destroy your saw blade or drill bit or cause dangerous sparks. You may need to switch to a different blade or bit to cut through rebar. You also may not want to cut it at all if you're planning on filling in the cut area with fresh concrete after your renovation project is completed.
Know the mixture of concrete beforehand
Concrete consistency will vary according to the surface; driveways and garage floors will be very solid and dense, whereas walkways around a patio or deck may be less solid as they won't need to hold up so much weight. If you use a blade or drill bit meant for soft concrete on the denser surfaces, you're likely to damage your tools and grind away the concrete, creating dust but not actually cutting. If you're renting concrete cutting tools, note the area to be cut to the rental agency and they can assist with finding the right blades and drill bits.
Be prepared for wires and pipes
Never assume that concrete will be free of electrical wires and other cables, plumbing pipes, and other such fixtures; these may be running through the concrete itself or they may be under the concrete slab. In some cases, these may be old and not in use, but they may also be live wires or plumbing pipes connecting your home's plumbing to the city pipes. Always cut concrete slowly so you don't hit any of these, keeping an eye out for such fixtures as you go.