I am trying to determine in rock wool prior to the Acoustical sealant is required on an STC 50 rating
Thanks for reaching out. STC rating depends on the firestop sealant and the assembly that was tested per ASTM E90. For example, FS-One MAX has STC of 62 as listed on the PDS of the product, and this rating relates to specific construction. Please send in a question case on Hilti Construction Platform and we can further look into your site condition and desired firestop products. You can find more information on how to access this new platform here: hilti.com/ej (US) or hilti.ca/ej (Canada.).
Fire Protection Engineering Team
Hilti North America
3701 W. Royal Lane, Suite 100 I Irving, TX, 75063
P 1-800-879-8000
E usfirestopeng@hilti.com
www.us.hilti.com/firestop