In Florida, a regulation informally known as the “25% Reroofing Rule” can be found in the 2020 (Seventh Edition) Florida Building Code– Existing Building Edition, specifically in Chapter 7 Section 706 EXISTING ROOFING. This rule has been part of the Florida Building Code for quite some time. Still, recent legislative changes, particularly Senate Bill 4-D, passed in 2022, have brought more clarity and modifications to its application.
Senate Bill 4-D introduced a new section, Subsection (5), in Florida Statute 553.844 titled “Windstorm loss mitigation; requirements for roofs and opening protection.” This subsection stipulates that regardless of other provisions in the Florida Building Code, if an existing roofing system or section was constructed, repaired, or replaced in compliance with the requirements of the 2007 Florida Building Code or any subsequent editions, and if 25 percent or more of that roofing system or section is now being repaired, replaced, or recovered, only the portion undergoing the repair or replacement needs to adhere to the current Florida Building Code. The Florida Building Commission is responsible for incorporating this exception into the Florida Building Code through official rules. Additionally, local governments are not allowed to enact ordinances that amend this exception.
This subsection is significant because it establishes an effective date after all properly permitted existing roof coverings are deemed compliant with the current code. That date is March 1, 2009, corresponding to the effective date of the 2007 edition of the Florida Building Code.
Under the Florida Building Code – Existing Building §706.1.1, no more than 25 percent of the total roof area or roof section of an existing building or structure can be repaired, replaced, or recovered within 12 months unless the entire roofing system or section complies with the code’s requirements.
The definition of a “roof section” can be found in the Florida Building Code – Existing Building Edition’s Chapter 2 Section 202 DEFINITIONS. It refers to a separation or division of a roof area by existing expansion joints, parapet walls, flashing (excluding valley), a difference of elevation (excluding hips and ridges), roof type, or legal description. It does not include the roof area required for a proper tie-off with an existing system.
To determine how the 25% rule applies, one must consider whether the current roof covering was permitted correctly after March 1, 2009. If it was, only the damaged area needs repair or replacement, regardless of size. If not, and the damaged area is less than 25% of the respective roof section, only that area needs attention. However, suppose the damaged size exceeds 25%. In that case, the entire roofing section containing the damage must be repaired or replaced, which may involve upgrades in the broken area.
It’s crucial to note that related work, defined in Section 502.3 of the 2017 (Sixth Edition) Florida Building Code Existing Building, which involves necessary components’ removal and installation to connect repaired areas to unrepaired areas (roof areas required for proper tie-off), is not considered part of the roof repair calculations as clarified in Declaratory Statement DS 2021-007 issued by the Florida Building Commission.
The 25% reroofing rule has experienced administrative changes to enhance its application, including the March 1, 2009 threshold date and reintroducing “related work” into the determination process, as per Declaratory DS 2021-007.