2024 Florida Roofing Code Changes

The implementation of the 8th edition of the Florida Building Code started in December 2023 and continues into the first six months of 2024. It’s part of a periodic update that takes place every three years. The 8th edition features significant changes impacting building construction, design, and roofing.

Roofing Changes – The 8th Edition 

The Code will address aspects like nail penetration and underlayment to enhance roof longevity and performance. This update removes specific scenarios in the 25% roof replacement guidelines, eliminating certain scenarios, so roofing professionals must stay up to date with these changes to stay in compliance with the Code.

Asphalt Installation & Underlayment

The updates make changes to section 1518.2.1, addressing the installation of underlayment and asphalt installation. The new guidelines state that contractors must use a dual layer of underlayment for metal, asphalt shingle, slat, alate shingle, and mineral surfaced roll roofing.


Underlayment must be ASTM D8257, ASTM D226 Type II, or ASTM D4869 Type III or IV. Installations must feature a strip of underlayment half the width of a full sheet for the first course, beginning at the eaves and properly fastened. The second course features a complete sheet of reinforced underlayment, beginning at the eave. 

Subsequent underlayment courses must overlap half of a full sheet plus 2”, with successive courses overlapping half of a full sheet’s width plus an inch.

Corrections to Section 1518.2.1 involve changes to the width of self-adhering modified bitumen membranes from 3-3/4” to 95 mm.

The update to the Code introduces underlayment improvements for installing a dual-layer system. This change is incorporated into the FBC residential section R905.1.1.1 in R10073-A3.

This proposal aims to extend the changes into section 1518.2.1 with the goal of establishing dependable requirements for dual-layer underlayment systems installed inside and outside of High-Velocity Hurricane Zones (HVHZ). 

Table 1518.2.1 shows two changes. The new standard is ASTM D6757, replacing ASTM D675. The second involves changes to minimum nail penetration depth through planks or sheathing. The depth changes from 3/16” to 1/8” to allow for consistency. 

The Code has introduced underlayment modifications focusing on installing mechanically fastened roofing tile systems using counter battens and direct-deck exclusively. According to reference 3.01E, roofs featuring a 4:12 pitch or greater or single-ply underlayment featuring direct-deck or battens no longer have the classification of the nail-on the underlayment.

The change to Roofing Application Standard (RAS) No. 120-20 addresses adhesive set and mortar tile applications. This change hopes to eliminate the term nail on systems with cap sheets and mechanically fastened base sheets set cold, hot, or self-adhered.  

The 25% Replacement Rule 

The Florida Building Code updated the 25% roof replacement rule, eliminating it in specific situations due to the enactment of SB-4D in May 2022. The 25% rule previously stated roof replacements are necessary if there is damage to more than 25% of the surface.

Roofs built after March 2009 likely feature compliance with the 2007 edition of the Florida Building Code. So, the changes require homeowners to repair the damaged section of their roof instead of replacing it if there is damage exceeding 25%.

Homes built before March 2009, with no prior roof replacement, are still under the last 25% rule. Therefore, they must undergo a complete roof replacement if they experience damage exceeding 25% of the total surface area. 

This exception features incorporation into the Florida Building Code via a rule adoption process managed by the Florida Building Commission. Contractors and homeowners should note that local governments can’t introduce technical or administrative amendments to the exception as per s. 553.73(4). 

The goal of the update to the 25% roof replacement rule aims to streamline roofing repairs and replacements, offering property owners increased cost efficiency and flexibility when settling on the right strategy for implementing projects to address damage to roofing systems. 

The Code offers a more pragmatic and practical approach to roof construction and maintenance by repairing affected roof segments rather than replacing the entire system. This change benefits both the building industry and homeowners in Florida.

Stay Compliant 

Roofing contractors and homeowners need to be aware of the changes to the Florida Building Code in 2024. Roofs must be contrasted or repaired in compliance with these changes. The discontinuation of the 25% roof replacement rule in specific situations makes it essential to promptly follow the latest regulation changes and address any damage to roofing systems.

At Southeast Waterproofing & Coatings, LLC, we are your trusted roofing experts in Florida. We provide comprehensive roof services, from inspections and maintenance to repairs and replacements. Contact us today via email or phone ((321) 225-0315) for a free quote. We are proud to serve Titusville, Orlando, Mims, Cocoa Beach, Rockledge, and Daytona Beach with our industry-leading service.

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