OVERVIEW
Where a wood-frame building does not satisfy the scope limits of the IRC, the fire-safety provisions of the IBC must be used. In addition to all other basic fire-safety requirements in the IBC (e.g., Chapters 3-10) and requirements for exterior walls (Chapter 14) and roofs (Chapter 15), specific requirements for use of FPIS are found in Chapter 26, particularly Section 2603.
In accordance with IBC Chapter 6, all light-frame wood construction is identified as “Type V” which, among other things, limits building heights and areas when using this type of construction. These limits and other requirements mentioned above are intended to limit risk and consequences of fire given that wood is a combustible material. Consequently, the provisions in Chapter 26, Section 2603 that apply to use of FPIS-ci on exterior walls of Type V construction are summarized as follows:
- Labeling and identification – required on materials or packaging; refer to IBC Section 2603.2.
- Surface burning characteristics – required; maximum flame spread index and smoke-developed index of 75 and 450, respectively (with various exceptions); refer to IBC Section 2603.3.
- Thermal barrier – required; typically not less than ½-inch-thick gypsum wallboard on interior side of wall or assembly tested per NFPA 275 (with various applications and conditions where thermal barrier is not required); refer to Section 2603.4.
DESIGN RESOURCES: For additional information on fire safety compliant design of exterior wall assemblies with FPIS-ci, refer to:
- Fire Performance - NFPA 285 Compliance
- Technical Evaluation Report: Foam Plastic Insulating Sheathing Products in Type V Construction
IMPORTANT TIP: The additional provisions of IBC Section 2603.5 for exterior walls of buildings of any height, do not apply to Type V (typically wood frame) construction. For example, the NFPA 285 vertical and lateral fire propagation test is not required because fire risk is adequately mitigated by other requirements for or limits of use of Type V (wood frame) construction. For information on other types of construction where the provisions of IBC Section 2603.5 do apply, refer to the Technical Evaluation Report: Foam Plastic Insulating Sheathing Products in Type I, II, III or IV Construction. Note that steel, concrete, and masonry construction may be used in Type V construction and avoid the requirements of IBC Section 2603.5 provided the building meets all the requirements for and limitations of use for Type V construction.