Direct Answer
For a low-slope commercial roof recover in Florida, the existing roof must be suitable to support the proposed roofing system, and the new assembly must satisfy applicable code, attachment, and wind-resistance requirements. Under the 2023 Florida Building Code, Building, the applicable section depends on the property’s location: Section 1511 covers existing roofing outside the High-Velocity Hurricane Zone (HVHZ), while Section 1521 addresses recover installations in the HVHZ.
Important section-number clarification: Section 1512 is part of the 2023 Florida Building Code’s HVHZ roofing provisions. For specific recover-installation requirements, verify Section 1521 in the HVHZ or Section 1511 outside the HVHZ. Do not apply the numbering from the International Building Code without checking the Florida amendments.
Who This Applies To
- Commercial building owners considering a roof recover instead of a full tear-off
- Facility managers responsible for low-slope membrane roofs
- Commercial roofing contractors and estimators
- Roof consultants, architects, and structural engineers
- Property owners planning reroofing work in Miami-Dade or Broward County
1. Confirm Whether the Existing Roof Can Be Recovered
A roof recover installs a new roof covering over an existing roof covering. It is not automatically permitted simply because the existing roof is flat or low-slope. The existing assembly must be evaluated against the applicable recover provisions, the proposed system’s approval and installation requirements, and the building’s structural and wind-load conditions.
Under the 2023 Florida Building Code, Existing Building, Section 706.3, removal of existing roof coverings down to the deck is generally required in specified circumstances, including when the existing roof is water-soaked or deteriorated and cannot adequately support another layer, when certain prohibited existing covering types are present, or when two or more roof-covering applications already exist. Applicable exceptions and HVHZ-specific provisions must also be checked.
2. Verify Attachment and Wind-Uplift Resistance
The new roof system must be attached in a manner that meets the applicable design pressures and code requirements. For HVHZ recover installations, Florida product evaluation reports reference Section 1521 and identify important verification steps, including:
- Mechanically attached systems: Fasteners installed into an existing roof deck may require withdrawal-resistance testing in accordance with Testing Application Standard (TAS) 105, with results reviewed by a qualified design professional.
- Adhered systems: The existing roof surface or substrate must be checked for compatibility with the proposed adhesive.
- Existing assembly performance: For an adhered recover, the existing roof system must be capable of resisting the applicable project design pressures. Field uplift testing in accordance with TAS 124 may be required to document performance.
The precise testing and documentation requirements depend on the system, existing conditions, approved assembly, and the authority having jurisdiction.
3. Maintain Positive Drainage on a Low-Slope Roof
Low-slope commercial roofs need to drain water effectively. Under the applicable reroofing provisions, qualifying existing low-slope roofs that provide positive drainage may be exempt from meeting the standard minimum design slope requirement of 1/4 unit vertical in 12 units horizontal (2% slope) for a new roof covering.
This is not permission to ignore ponding or drainage defects. The existing roof must satisfy the applicable conditions for the exception, and the project should preserve functional drainage paths, drains, scuppers, and related details. Additional requirements may apply in the HVHZ.
4. Check Roof Edges, Flashings, and Product Approvals
A recover project involves more than installing a membrane over the old surface. Contractors should also confirm:
- The proposed roof assembly has the required Florida approval or other applicable acceptance.
- Perimeter securement and edge-metal details meet applicable wind-load requirements.
- Flashings, penetrations, curbs, and transitions are compatible with the new roof system.
- The existing substrate is sound and suitable for the proposed attachment method.
- Required permits, inspections, and supporting documentation are in place.
5. What Should Contractors Check Before Starting?
- Confirm whether the property is within the HVHZ, which includes Miami-Dade and Broward Counties.
- Identify the code edition and local requirements applicable to the permit.
- Document existing roof layers, moisture, deterioration, and deck conditions.
- Determine whether recover is permitted or whether tear-off is required.
- Verify attachment, wind-uplift performance, drainage, and product approvals for the proposed assembly.
- Consult the local building department or a qualified design professional where the requirements are uncertain.
Bottom Line
For an existing low-slope commercial roof, a recover is allowed only when the existing roof and proposed new assembly satisfy the applicable code requirements. Under the 2023 Florida Building Code, Building, Section 1511 generally applies outside the HVHZ, while Section 1521 addresses recover installations in the HVHZ. Section 1512 is part of the HVHZ roofing provisions, so verify the exact section and applicable requirements before preparing a permit or specifying the roof system.
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 is the difference between static and cyclic wind uplift testing?
Sources
- Florida Building Commission — Official Building Code Resources
- Florida Roofing Association — 2023 Florida Building Code Roofing Updates
- Florida Product Evaluation Report — HVHZ Roof System Limitations and Recover Requirements
- Florida Product Evaluation Report — Recover Installation and Testing Considerations
- 2023 Florida Building Code, Building — Eighth Edition
Last reviewed: October 2026
Related Resources
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Before choosing a roof recover, have the existing roof condition, drainage, attachment method, and wind-uplift requirements evaluated. A professional assessment can help determine whether recovering is appropriate or a full roof replacement is needed.
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This article provides general educational information about roofing code requirements. Applicable provisions depend on the adopted code edition, location, roof system, and project conditions. Consult the applicable code and local building official for project-specific requirements.
