30 sf re-roof () if a re-roof project is proposed, the following specifications apply. Existing roofing material comp shingles proposed roofing material comp shingles manufacturer owens corning brand and model oakridge color (if cool roof required) not req used sierra gray built-up roofing assembly system number per attached listing report (if applicable) n/a specific exemption from cool roof requirements (if applicable) n/a required building inspector field verification (if applicable) n/a note self-certification by a licensed contractor is acceptable if a signed letter on company letterhead is provided to the building inspector.