Both estimates should provide contact details for the roofing firm, including company name, location, telephone number and e-mail address. A very detailed summary of the work to be performed should be included in the roofing calculation. Both roofing materials, underlay form and width, flashing positions, and even the size of nails and fasteners to be used should be specified. The start date is the day the roofing contractor begins construction on your roof. You need to make sure that the date suits your expectations and timetable. All materials that will be used to complete the roofing work are important for cost estimation. This covers any shingles, flashes, soffit elements, gutter parts to be removed, and any other items and materials that your roof may need. Any new roof calculation would need to include the actual project expense that you will have to pay for the work you have completed. Compare the expenses of the contractors in order to decide what is fair. Check each estimation to see what kind of promises each roofing contractor gives. The calculation should also contain a section on workmanship assurances, inventory guarantees and goals.