Firestopping head of wall joints seems basic, but its shocking how often something so basic is done so wrong. If your project has shaft walls and you are fire stopping them with sealant, please watch this video, so you can be sure the installations on your projects meet the requirements.
First thing to check- Do your firestop submittals have shaft wall details? If not, they should. If not, there is a considerable risk that the fire rating of your shaft walls is missing the requirements we point out in this video. If you want to know how to avoid this liability, this video is designed to help.