- 45 sqft re-roof for existing sfd if a re-roof project is proposed, the following specifications apply. Existing roofing material comp proposed roofing material comp manufacturer owens corning brand and model oakridge color (if cool roof required) sierra gray built-up roofing assembly system number per attached listing report (if applicable) specific exemption from cool roof requirements (if applicable) no required building inspector field verification (if applicable) yes note self-certification by a licensed contractor is acceptable if a signed letter on company letterhead is provided to the building inspector.