2600sf re-roof for existing sfd if a re-roof project is proposed, the following specifications apply. Existing roofing material comp shingles proposed roofing material comp shingles manufacturer gaf brand and model timberline color (if cool roof required) built-up roofing assembly system number per attached listing report (if applicable) specific exemption from cool roof requirements (if applicable) r38 in attic required building inspector field verification (if applicable) note self-certification by a licensed contractor is acceptable if a signed letter on company letterhead is provided to the building inspector.