The Metal Building Manufacturers Association (MBMA) has just released the results of a study on fire protection alternatives for metal buildings. The research report, W/D Study of Non-prismatic (built-up) I-shaped Framing Members in Metal Buildings, was undertaken by Nestor Iwankiw, PE, SE, Ph.D., of Jenson Hughes. The executive summary of this research is available for download at the MBMA blog.
“This research fills an important gap in fire-protection data for metal building systems,” notes Lee Shoemaker, PE, Ph.D., MBMA’s director of research and engineering. “It demonstrates that alternative fire protection materials and products can be specified to accommodate various architectural schemes.”
When fire protection of metal building frames is required by the building code, the assemblies have historically been gypsum board enclosures, such as UL Design No. X524. For this study, 180 single-story metal building designs that varied in span length, roof slope and location in the continental United States were tested. The weight-to-heated-perimeter ratio (W/D) values of the rigid frame members were determined for the metal building designs.
The study results indicate the opportunity for increasing applications of spray-applied products and intumescent/mastic coatings in metal buildings for structural framing members with a W/D of at least approximately 0.30 lb/ft/in. in column assemblies, such as UL X632, X649, X772 and X829. The results encourage alternative potential uses of spray-on protection in industrial or warehouse metal buildings when a finished interior appearance with gypsum board is not necessary.
The project was undertaken under the auspices of the MBMA Fire & Insurance committee. In addition to this new document, MBMA’s website has a series of insurance bulletins that are free to download. Additional manuals and publications for purchase, including the Fire Resistance Design Guide for Metal Building Systems, are available at www.mbmamanual.com.