Good afternoon,
I am looking to a bridge a connection between a masonry wall to a 6x6 HSS column to a curtain wall mullion. Is there 1 or 2 UL assemblies and/or listing that can complete this condition without the need for an EJ when submitting to the building department? Our commercial building is in Dallas. The masonry wall will need to be 2-HR rated due to it being part of an interior exit stair enclosure. Primary steel throughout the project will be 1-HR rated, the HSS column will be in-line with the masonry partition and will have intumescent paint to continue the 2-HR rating of the masonry wall at this condition. The curtain wall does not need to be rated.
Our team is open to suggestions for how to make this work. As of now the idea is that the ~1" gap between the fully grouted CMU masonry wall and the HSS columns will be filled with mineral wool and the outside will be enclosed with intumescent tape. The connection between the HSS column and the mullion could be bridged with the 2-HR rated 60 Classic Mullitover mullion encasement (UL ASSEMBLY NO: WW-S-1041). The encasement would attach to L angles on either side of the flange that are painted with intumescent paint.
Thanks for your firestop request. To treat a joint between a vertical fire barrier and non-rated exterior curtain wall, we can provide Code Evaluation Detail, CED, per International Building Code 2018. IBC code section 715.4.2 states the following:
Voids created at the intersection of non-fire-resistance-rated exterior curtain wall assemblies and fire barriers shall be filled. An approved material or system shall be used to fill the void and shall be securely installed in or on the intersection for its entire length so as not to dislodge, loosen or otherwise impair its ability to accommodate expected building movements and to retard the passage of fire and hot gases.
Based on this code language, Hilti can provide Code Evaluation Detail. This detail is code compliant and will be subject to the approval of the Authority Having Jurisdiction. In order to provide a CED, we will need an EJ Request. Please submit your EJ request using links: https://www.hilti.com/ej (US) or https://www.hilti.ca/ej (Canada.)