New BXUV Guide Guidance for Fire-Resistance-Rated Mineral and Fiber Board Products

Authored by:

Kevin Hyland, Principal Engineer, Fire Resistance and Containment, Built Environment, UL Solutions, and Distinguished Member of Technical Staff — William Henry Merrill Society   

As the use of mineral and fiber board in fire-resistance applications continues to grow — particularly in projects such as data centers — it is important for code officials, designers and installers to be aware of new guidance recently added to the BXUV Guide. This new section highlights critical installation considerations for maintaining the fire-resistance ratings established through testing and certification. 

Spray-applied fire-resistive materials (SFRMs) and intumescent fire-resistive materials (IFRMs) are commonly used to protect structural steel elements, including beams, joists, columns and steel deck assemblies. Another widely used option is mineral and fiber board. 

Mineral and fiber boards are manufactured from materials such as stone wool (mineral wool), glass fibers, proprietary binders and other components formed into rigid boards. These boards are produced in a range of thicknesses and are cut and installed around structural steel members to provide fire resistance. 

Several manufacturers have demonstrated the fire resistance performance of these products through testing in accordance with UL 263, the Standard for Fire Tests of Building Construction and Materials, and ASTM E119, Standard Test Methods for Fire Tests of Building Construction and Materials. This testing method is recognized by model building codes as a means of establishing compliance with fire-resistance requirements. 

When testing successfully establishes a fire-resistance rating, the product becomes eligible for UL Certification and UL Solutions Follow-Up Services. Certified products can bear the UL Certification Mark for fire resistance, and the manufacturer name and product designation can be found under Product iQ® category codes CERZ and BZJZ. Product iQ is available at no cost but requires a one-time registration. 

In addition, a UL fire-resistance-rated assembly (design) is established that specifies the materials, construction methods and installation details necessary to achieve the rating. These designs can be found in the D300, G300, J300, N300, P300, S300 and X300 series within Product iQ.  

To support the proper application of these designs, the BXUV Guide now features a section titled “Board Fire Protection Products.” This section consolidates important installation guidance and limitations applicable to mineral and fiber boards, including: 

• Exterior applications 
• Limitations on use with dissimilar fireproofing materials 
• Limitations on increasing board thickness beyond tested configurations 
• Limitations on the use of alternative thickness equations contained elsewhere in the BXUV Guide 
• Restrictions on substitutions between open steel sections and hollow steel sections 

Similar provisions have long existed for SFRM and IFRM designs. However, with the increasing use of mineral and fiber board products, it became important to clearly identify and reinforce the applicability of this guidance to board-based fire protection systems as well. 

Code authorities, designers, contractors and installers are encouraged to review the new “Board Fire Protection Products” section in the BXUV Guide to help keep installations consistent with the conditions under which the fire-resistance ratings were established. 

For more information, refer to the complete addition to the BXUV Guide.