By the way "instillation" = "insulation"...stupid smart phone auto correct
For more info on the collar, I used 2x10 to make the inner collar and then 1x12 as a decorative "paneling" to lock in the collar to the freezer. So the 1x12 is even with the top of the 2x10 and overlaps the freezer by almost 2 inches on three sides (I didn't do the back because no one will see it). However, I did use some spare 1x12 scraps, about 6 inches on the Left and the Right edges on the back to ensure the collar is locked in on all 4 sides.