Can W-L-0040 Installation

Steve,

From a firestop standpoint, adding additional gypsum for a backer as detailed in your sketch will not negatively affect the performance of the system. However, since the additional gypsum is not called out in W-L-0040, it is up to your Authority Having Jurisdiction to determine if you can use the system as is or if you need to request for an Engineering Judgment, which will be a custom detail showing your exact application with the firestop components required to maintain the stated ratings. Should you need an Engineering Judgment, see the below information.

Hilti is proud to announce the launch of our engineering website, the HILTI CONSTRUCTION PLATFORM (HCP). This platform will be the home for all of your Fire Protection Engineering needs, including Engineering Judgment requests. You can find more information on how to access this new platform here: https://www.hilti.com/ej (US) or https://www.hilti.ca/ej (Canada.)

Along with HCP, Hilti is excited to announce our new mobile app for all your firestop needs: Hilti Firestop Selector. Using the Firestop Selector app gives you easy access to the Hilti Fire Protection Design Team from the jobsite, on the road, or in the office to request a new EJ, an EJ Revision, or ask a Question anytime, anywhere. You can download the app using the Google Play Store or Apple App Store.

If you have any questions, please reach out to our customer service team at 1-800-879-8000 (US) or 1-800-363-4458 (Canada) for assistance.

Thank you,

Jessica Starks
Senior Fire Protection Engineer