The Weekly Fix is a home maintenance column by Home Repair Resource Center, a Cleveland Heights nonprofit that helps homeowners buy, repair and retain their homes. Each week, the center offers a seasonal home maintenance tip. For more information on its services, call 216-381-6100.
Homeowners who do their own repairs may need to cut out an area of concrete (to replace a sidewalk block, repair a basement drain line, etc.) The best tool for this job is a concrete saw; however, if you don't have access to one, a circular saw can sometimes work if you take proper precautions.
A diamond blade with diamond-tipped teeth is pricey, but will last the longest. If you're not cutting a lot, you can probably get away with an abrasive masonry-type cut-off blade. This blade wears down rather quickly, so buy some extra and return any that you don't need. The blades are available at hardware stores, lumberyards, building supply stores, etc.
Cutting a straight line will lessen the stress on the blade; use a chalk line or other straight-edge tool to mark where you'll be cutting. To prolong the life of the blade and reduce the chance that it will break up, make several shallow cuts, rather than one deep cut.
When cutting concrete, observe several safety tips to help prevent serious injury. First, wear a protective face shield, or at least safety glasses. Masonry-type cut-off blades are brittle and disintegrate easily; since the blade turns so fast, the pieces can fly off at high speed and be very dangerous. In addition, the small stones that make up the concrete can fly up and hit you as you cut.
Second, be aware that cutting concrete is very dusty. Protect yourself with a dust mask and, if cutting inside, use tape and .3 mil sheet plastic to close off the work area and cover furniture, windows, doorways, and ducts. Don't run your furnace or air conditioner during the work, as the dust can damage furnace components and be re-distributed all over the house. If possible, saturate the area with water as you cut to keep dust to a minimum.
Use the saw in a position where you're comfortable and secure. If you're off balance, you'll be worrying about keeping your footing, and less aware of using the saw safely.
Don't wear loose clothing that can get caught in the saw blade.
Finally, don't force the saw. Let it cut at its own rate, with only enough pressure to keep it on course.