Direct Answer
The Florida Building Code, Existing Building, governs how reroofing work on an existing building is classified and performed, while the Florida Building Code, Building, provides the technical requirements for roof assemblies, materials, and installation. Under the 2023 Florida Building Code, Existing Building, Chapter 7, Section 706 addresses existing roofing, including reroofing, recovering, and replacement. Section 706.1 directs materials and application methods for new roof coverings to the applicable roofing provisions of the Building or Residential volume.
In simple terms, the Existing Building volume addresses the rules for working on an existing roof; the Building volume supplies many of the technical requirements for the replacement or recovered roof system. Both may need to be considered for a commercial reroofing permit.
Who This Applies To
- Commercial property owners planning roof replacement or recover projects
- Facility managers and building owners maintaining existing properties
- Commercial roofing contractors and estimators
- Architects, engineers, and building-code consultants
- Property managers coordinating reroofing permits and inspections in Florida
1. What Does the Existing Building Volume Cover?
The Florida Building Code, Existing Building, applies to work on existing buildings, including repairs and alterations. For reroofing, Chapter 7, Section 706, titled “Existing Roofing,” contains provisions specifically addressing existing roof systems.
These provisions help determine how the work must be handled, including whether existing roof coverings may remain, when removal is required, and which requirements apply to the new roofing materials. The exact requirements depend on the scope of work, existing roof conditions, building characteristics, and applicable code edition.
2. What Does the Building Volume Cover?
The Florida Building Code, Building, contains technical requirements for roof assemblies and roof coverings. Chapter 15 addresses roof assemblies and rooftop structures, including applicable requirements for materials, installation, and roof-system components.
For reroofing, the Existing Building volume directs the installer to the relevant roof-covering requirements in the Building volume or, where applicable, the Residential volume. Other provisions may also apply, such as structural design and wind-resistance requirements.
| Consideration | Existing Building volume | Building volume |
|---|---|---|
| Primary role | Rules for repairs, alterations, and work on existing buildings | Technical requirements for building systems and construction |
| Reroofing provisions | Chapter 7, Section 706, Existing Roofing | Chapter 15, Roof Assemblies and Rooftop Structures |
| Existing roof coverings | Addresses when existing materials may remain or must be removed under applicable provisions | Sets applicable requirements for the new roof covering and assembly |
| Installation requirements | Directs reroofing work to the applicable roofing provisions | Provides relevant technical requirements for materials and installation |
| Project application | Helps establish which rules apply to the existing-building work | Helps establish how the new roofing system must comply |
3. How Section 706 Applies to Commercial Reroofing
Section 706 of the 2023 Florida Building Code, Existing Building, contains specific requirements for existing roofing. Section 706.1 addresses the materials and methods used to recover or replace an existing roof covering, directing them to the applicable roofing requirements in the Building or Residential volume.
Section 706.3 addresses recovering versus replacement. Under the applicable conditions, new roof coverings cannot simply be installed over all existing roof layers. For example, removal down to the roof deck is required when the existing roof covering is water-soaked or deteriorated to the point that it cannot adequately support another roofing layer. Certain existing roof-covering materials also trigger removal requirements.
Contractors should review the complete section and applicable exceptions before deciding whether an existing roof can be recovered or must be removed.
4. Does the 25% Roof Rule Apply?
The traditional 25% provision is another important consideration in Florida reroofing projects. The applicable code language generally limits the portion of an existing roof area or roof section that may be repaired, replaced, or recovered during a 12-month period unless the relevant requirements for the entire roof system or section are met.
However, Florida Statutes Section 553.844(5) provides an exception for qualifying roofing systems or roof sections built, repaired, or replaced in compliance with the 2007 Florida Building Code or a subsequent edition. Under that exception, when 25% or more is being repaired, replaced, or recovered, only the portion being worked on is required to comply with the code in effect, as applicable.
Do not rely on the 25% threshold alone to determine the scope of work. Confirm the applicable code edition, statutory exception, roof-section definition, permit history, and local building department requirements before proceeding.
5. How Should Contractors Approach a Commercial Reroofing Project?
- Inspect the existing roof. Document the existing covering, roof deck, moisture damage, deterioration, and any known prior roof layers.
- Classify the work. Determine whether the project involves repair, recover, or replacement under the applicable code provisions.
- Review Section 706. Check the Existing Building volume for reroofing requirements, including removal conditions and applicable exceptions.
- Verify technical roof requirements. Review the applicable Building volume provisions for the proposed roof assembly, installation method, wind resistance, and approved products.
- Confirm permit requirements. Coordinate with the local building department and retain required product approvals, plans, and installation documentation.
Florida’s 2023 code edition is the Eighth Edition, with subsequent supplements. The Ninth Edition is scheduled to take effect on December 31, 2026, so verify which edition and supplements apply to the project and permit date.
Bottom Line
The Florida Building Code, Existing Building, Chapter 7, Section 706 governs key aspects of reroofing existing buildings. The Florida Building Code, Building, Chapter 15 provides the applicable technical requirements for roof assemblies and coverings. Commercial reroofing projects may need to comply with both volumes, along with other applicable provisions and local requirements.
Related Questions
- What happens if I install a commercial roof without proper product approval?
- When is it better to replace a commercial roof rather than repair it?
- What are common red flags in commercial roof condition reports?
Sources
- Florida Building Commission — Official Building Code Resources and Supplements
- Florida Roofing Association — 2023 Florida Building Code Roofing Updates
- 2023 Florida Building Code, Building — Eighth Edition
- Florida Division of Emergency Management — 2023 Florida Building Code, Existing Building reference document
- Florida Statutes, Chapter 553 — Building Construction Standards
Last reviewed: October 2026
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This article provides general educational information about Florida roofing code requirements. Applicable provisions may vary by code edition, supplements, local amendments, building conditions, and project scope. Consult the adopted code and local building official for project-specific requirements.
