The combination of the two guiding installation standards for LPS—NFPA 780 and UL 96A—being added to the code, and concerns from SPRI members about how lightning system are attached, precipitated the need for SPRI to act to address this situation and the code update.
A task force was established to seek and build cooperation between the commercial roofing and lightning protection industries, with the goal of clarifying the code language regarding how LPS, when used, should be secured to the roof or perimeter edge metal system without negatively impacting the wind rating or system performance.
Initial meetings and discussions were held with LPI, UL Solutions, the National Electrical Manufacturers Association (NEMA), and NFPA, who were all interested in working together for clarification to the language, which would come in the Group B code development cycle in 2022.
Following these discussions, and as part of the Group B Cycle, a proposed new language was drafted and sent to the organizations that SPRI had been working with, and submitted in January 2022, as an update to Chapter 15, “Rooftop Structures,” which had not been updated in the earlier review cycle.
The wording added to Chapter 27 in the first phase of the code update was focused on installing lightning protection, but there was nothing about maintaining or protecting the integrity of the roofing system, which is covered in Chapter 15 of the code and a critical consideration in the process. The specific original wording (S43-22) was as follows:
[BG] 1511.7, Other rooftop structures. Rooftop structures not regulated by Sections 1511.2 through 1511.6 shall comply with Sections 1511.7.1 through 1511.7.5 6, as applicable.
1511.7.6, Lightning Protection Systems. Lightning protection system components shall be installed in accordance with Section 1511.7.6.1. Lightning protection systems shall not be attached directly to metal edge systems, including gutters, where these roof assembly components are required to be tested to ANSI/SPRI/FM 4435-ES-1 or ANSI/SPRI GT-1 in accordance with Sections 1504.6 or 1504.6.1.
Exception: Where permitted by the manufacturer’s installation instructions for the metal edge systems or gutters.
1511.7.6.1, Installation. Lightning protection system components directly attached to or through the roof covering shall be installed in accordance with this chapter and the roof covering manufacturer’s installation instructions. Flashing shall be installed in accordance with the roof assembly manufacturer’s installation instructions and Sections 1503.2 and 1507 where the lightning protection system installation results in a penetration through the roof plane.
