Roofers use a sharp utility knife for most of the cuts necessary during a shingle project. The replaceable blade of the utility knife can be retracted for handling safety when not in use. The cut is made on the underside, the side without the stone aggregate, before the shingle is flexed to break at the score. A straight edge, often a carpenter's square, is held on the shingle and serves as a guide during cutting.
Use a tape measure to determine the lengths of roofs and locate centers of roof for starting the bottom course of shingles. Mark positions on the roof deck boards with a standard carpenter's pencil. A chalk line marks straight lines over longer distances and is used as a reference to keep rows of shingles straight. A chalk line is a string, stored in a container filled with loose chalk, stretched tight between two points. When the string is pulled up it snaps back into place leaving a line of chalk on the roof deck as a reference line.
Roofers use the basic claw hammer to drive nails through the shingle into the roof sheathing. Hammer and nails is the old-fashioned way but still works well and is the most economical method for small projects. Nailers, power tools using compressed air or electricity for power, drive specialized nails or staples through the shingles into the roof sheathing. Nailers are more labor-efficient than hammers and can be rented from building supply stores.
Not all tools are used in every roofing project. Use a tin snip to cut flashing tin used in the valley between two segments of roofs. Organize all the tools in a tool belt for easy access while working. A proper ladder and scaffolding is also necessary for safe access to the roof.