B and C Well-known member Joined Dec 8, 2014 Messages 5,283 Reaction score 14 Location Atascocita, TX Sep 17, 2019 #21 The 2x2 becomes structural and stiffens the opening. The fan is screwed into it and the trim ring is screwed to it.
The 2x2 becomes structural and stiffens the opening. The fan is screwed into it and the trim ring is screwed to it.