Interpretation #7504

Reroofing is the act of recovering or replacing an existing roof system. Requirements for reroofing are found in the FBC, Existing Building Volume section 611. Section 611.7 requires roof deck attachment verification or renailing in the event the existing roof is removed and replaced. In this scenario the existing roof is not to be removed. However, Section 611.3 sets the criteria for establishing when recovering rather than roof replacement can take place. Where any of the five listed items apply, a roof recover cannot take place. Item number 5 may be a concern. This item indicates if an existing roof is to be used for the attachment of a new roof system the securement provisions of Section 1504.1 must be met. This section requires the roof deck be in compliance with the wind load provisions of Chapter 16. If the deck is not adequate to meet the wind design requirements a recover would not be allowed. Nevertheless, Section 611.3 contains five exceptions. Exception #2 applies if a complete and separate roofing system, such as standing-seam metal roof system, that is designed to transmit the roof loads directly to the building�s structural system and that do not rely on existing roofs and roof coverings for support, may be installed over an existing roof system. Such as a metal roof system on purlins. Also see Informal Interpretation #7415, which is generally related to this question.