What is the minimum joist height required for installation?
Given the existing faceplate size and assuming a 5 1/4″ hole in the ceiling, the joist should be 8″ high. However, if the joist is 6″ the Guardian Fire Shield can still be installed, a larger hole would need to be cut and the extra space would need to be covered by some custom covering, since our faceplate wouldn’t completely hide a larger hole..