Specifically engineered manufacturing processes create mineral wool that will perform in extreme conditions. These processes deliver properties that allow the mineral wool to withstand extreme heat and maintain its structural integrity under intense fire exposure. For example, the mineral wool in an ASTM E2307 compliant system must demonstrate its ability to withstand direct flame impingement and temperatures exceeding 982 C (1,800 F) while retaining its stability. The stability of the material is essential when one considers the relatively lightweight components in the curtain wall, such as aluminum and various components, may start to deflect, melt, or show signs of failure as early as nine minutes into a fire. With all these performance requirements in mind, ASTM E2307 subjects firestopping materials to the extreme temperatures and pressure that occur during a commercial high-rise fire.
Testing conducted by this author’s company investigated how various types of mineral wool perform. The testing found a standard mineral wool industrial or acoustical board at 101.6-mm (4-in.) thick and with a density of 64.1 kg/m3
(4 pcf) does not provide the same level of fire protection as a certified curtain wall or safing insulation in an ASTM E2307-tested and -classified system. Specifiers should ensure firestopping materials including mineral wool and other components are tested to ASTM E2307.
Appreciating the role manufacturing plays in supporting mineral wool’s performance in perimeter fire containment systems makes it clear why the specific mineral wool insulation used in PFC systems, including pre-insulated panels, needs testing and verification to be implicit in third-party listing organizations and verified by ASTM E2307. Such third-party validation provides specifying architects and contractors, as well as building owners and occupants, with an independent measure of assurance that the firestopping materials installed can help withstand conditions and characteristics of a high-rise fire in commercial buildings and ensure safety.
Resisting pressure to downsize testing
While this article focuses on mineral wool used in firestopping applications, it should be noted ASTM E2307 assesses every component’s performance in the PFC system and how they work together to support system performance. Every fire is unique, but as the comprehensive design of ASTM E2307 considers the whole system, this test provides a more holistic approach to vetting the system, compared to testing where components are evaluated individually.
