A roof is consistently exposed to the elements. If your roof isn't taken care of, molds, mildew and debris can build up. It is important you have the correct tools to take maintain your roof. Make sure you have a utility knife. Utility knives can be used to cut drywall, trim asphalt roof shingles, and slice through fiberglass insulation. Utility knives are relatively safe to use since the razor-sharp blade can be retracted. Besides a utility knife make sure you buy a roofing hammer with a straight claw. To cut wood, shingles or roofing panels, a circular saw would be a worthwhile investment. This electrically-powered tool can cut roof panels and plywood sheathing into an array of different sizes. To hammer nails in, abandon the manual hammer and opt for a nail gun. Compressed air is used to force the nails from the loaded gun strip unto the sheathing or shingles.home roofing replacement estimate O'Fallon