MBMA Announces New UL Fire-Resistance-Rated Designs for Wall-Roof Joints and Intersections

Date:July 27, 2021
Contact:Tony Bouquot, General Manager

The Metal Building Manufacturers Association (MBMA) announces six new UL fire-resistance-rated designs for wall-roof joints and intersections in metal buildings. These latest UL head-of-wall assemblies enable common fire-rated wall-roof joints and intersections to meet more stringent energy code requirements while maintaining fire safety. They are available via www.mbma.com/Fire_Protection.html.

The new UL designs for wall-roof joints between fire-rated assemblies are HW-D-0926, HW-D-0927 and HW-D-0928. For intersections between a fire-rated wall and a non-fire-rated roof, the new UL designs are CJ-D-0029, CJ-D-0030 and CJ-D-0031.

“MBMA’s existing HW-D/CJ-D head-of-wall assemblies, which became available in 2008, have worked well,” notes Vincent E. Sagan, PE, senior staff engineer for MBMA, “but due to changes in the energy codes, a greater amount of roof insulation is often required to be compliant. UL performed engineering studies to demonstrate compliance with building codes, resulting in the six new fire-rated assemblies.”

The new HW-D/CJ-D head-of-wall assemblies allow for significantly greater levels of insulation. The existing designs called for a single layer of faced glass-fiber blanket insulation, compressed between the metal roof panels and the top of the interior wall. The new UL designs still call for a layer of insulation between the metal roof panels and the top of the wall, but allow for additional insulation, glass fiber or mineral wool, as well as a vapor barrier, as found in filled cavity insulation systems and liner insulation systems.

“With the new UL designs,” adds Tony Bouquot, MBMA’s general manager, “fire-barrier walls can be designed and constructed in metal buildings that meet current energy and fire safety code requirements. Thanks to MBMA’s Fire & Insurance Committee, which has been working diligently to stay on top of these changes, we can help to ensure metal building systems continue to be the preferred construction choice in the low-rise commercial building market.”

More than 20 fire-resistance-rated assemblies for metal buildings are available on the Fire Protection page of the MBMA website, www.mbma.com/Fire_Protection.html. Additionally, MBMA’s “Fire Resistance Design Guide for Metal Building Systems” is available at www.mbmamanual.com.

For additional questions or inquiries about metal building fire protection, please contact Vincent Sagan at mbma@mbma.com.