Yes, The information on reroofing with all applicable definitions was taken from the FBC- Existing Buildings volume and added back into the FBC- Bldg. Otherwise, you would be looking specifically in the Existing code book for all these reroof concerns. In the FBC-Existing Buildings, whether using the compliance method in Chapter 4 or Chapter 6. The Existing code accepts materials and methods that were approved at the time of the building construction, if permitted. Repairs can be made in similar fashion as long as it is not making it any less conforming than it was before the repair was undertaken.