Reece, the code on this is pretty clear in it’s intent. If the decking is visibly damaged or “water soaked” it must be replaced…agruing that the decking wasn’t visible at the topside as damaged doesn’t remove you from liability. Ultimately, through statutes 489 & 455, you are responsible for determing proper attachement and condition of the deck for attachement of the roof covering.
The building code does define “roof assembly” as inclusive of the deck and roof covering…
**ROOF ASSEMBLY. **A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder, and roof covering.
…also, the Existing Building Code on reroofing:
2010 Florida Building Code: Existing Building: 611.3 Recovering versus replacement. </B>
New roof coverings shall not be installed without first removing all existing layers of roof coverings where any of the following conditions occur:
- Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.