How to Cut Through a Tar Roof
Tar roofs are often topped with gravel, which can quickly wear down standard saw blades. Roofing tar itself melts when heated, and can stick to and gunk up blades with closely spaced teeth. Special circular saw blades with wide-set teeth are designed to cut through tough materials and won’t heat up as quickly as other blades. Firefighters use these types of blades to cut through roofs during rescue operations. Homeowners looking to install a skylight in a tar roof or make other repairs that call for removing a portion of their tar roof can borrow the technique from first responders.
Put on safety goggles to protect your eyes from debris as you cut through the roof.
Fit the circular saw with the carbide chunk blade. Set the saw’s blade to the desired depth. Cutting through the tar material and sheathing will typically require a depth of 1 to 1 1/4 inches.
Hold the saw’s blade 1 inch above the roof, remove the blade guard and depress the trigger until the blade accelerates to full speed. Lower the blade and push it forward carefully to cut through the roof.
- Safety goggles
- Circular saw
- Carbide chunk blade
- Choose a calm, clear day to work on the roof. A wet roof surface can be slippery, and wind can knock you off balance.
- Wear clean, dry shoes with rubber soles to improve traction when walking on the roof. Tread lightly and carefully.
- Watch the circular saw's extension cord to avoid tripping on it.
- Use roof brackets and a harness for maximum safety.
- Avoid cutting rafters and joints. To mark their location, drill a hole through the roof sheathing from the attic side and push a screw or bolt through the hole to make it easy to see from the roof side.