PV AND ROOF FIRE CLASSIFICATION RESEARCH PROJECT

The Solar ABCs and UL have an ongoing research program for photovoltaics (PV) and buildings.  This work, funded by the U.S. Department of Energy, has the goal of developing effective codes and standards that ensure safety for buildings with roof-mounted PV systems.  Work continues related to basic fire research, development of new test standards, and outreach of practical information to PV manufacturers, installers, professionals in the building codes enforcement and firefighting communities. 

The multi-phase project addresses the impact of PV installations on the fire classification rating of roofs. Findings indicate that the fire classification rating of the PV module is not a good indicator of the impact a rack-mounted PV system may have on the fire classification rating of the roof.  The research found examples where both Class A and Class C rated PV modules can cause the fire classification rating of the roof to degrade. At the same time, installation of Class A/Class C rated PV modules in other configurations do not cause the fire class rating of the roof to degrade.

Concurrent with the research, changes have been made to the International Building Code (IBC) and the International Residential Code (IRC) 2012 editions that impact photovoltaic installations.  These codes include requirements for building-integrated photovoltaic (BIPV) products and for rack-mounted photovoltaic products.  These codes include requirements for fire classification, wind resistance, installation and materials.  Until a new system PV fire classification test is finalized, the fire classification requirements may not be easily applied.

As a result of the research and in consideration of current requirements of IBC Section 1509.7.2, the Solar ABCs/UL are working with the ANSI/UL 1703 Standards Technical Panel (STP) to develop a new system test methodology, in close association with PV industry, roofing industry, standards development, building and fire enforcement community and government laboratory experts.