Why there is no promise that your one hour rated wall will last for one hour in a fire.

Before Covid I did a lot of training classes. One day in class I had a guy get mad at me when I told him there was no promise that a one hour rated wall would survive a fire for one hour. Talk about shoot the messenger! But understanding this is important for anyone who designs builds or inspects. That is the topic of this “Firestop Coffee Break Training”. Please join me.