I have a 1 hr fire rated exterior wall with metal stud construction, it balloon frames past the floor slab. Here is my question, is fire stopping required within the exterior fire rated wall system in line with the floor slab? We will have FireStopping between the rated wall assembly interior membrane and the edge of slab.
Hello Ryan,
If the exterior wall assembly is a vertical fire barrier and carries a fire rating, the joint would need to be considered as a UL 2079 joint system and firestopped as if it were a floor-to-wall joint rather than a perimeter fire barrier. For this type of joint, we could address your condition with an engineering judgment.
For non-rated exterior construction where the balloon stud framing "flies-by" the edge of slab, the joint should be treated per the appropriate listed system. For Hilti, the most common system we would recommend is HI/BP 120-03 (attached). For this method, you would see the firestop material extending into the cavity of the exterior wall assembly.
If you need to proceed with the engineering judgment, please fill out and email the completed form with any additional details to usfirestopeng@hilti.com If you have any questions, comments, or concerns please feel free to call or email us.
Thank you for choosing Hilti as your firestop specialist and have a great day.
Regards,
Nate Crawford
Senior Fire Protection Engineer
