I understand that drywall can be glued and screwed, creating air-tight "duct" in a stud bay.
But what about wall that's finished in T&G, on both sides? Will have following return sizes (measurements are for floor sill plate cut area):
- 2x 9x9"
- 1x 8" round
- ~5x 3-1/2"x14-1/2" (regular 2x4 16"OC cavity)
Planned for low and high return with closeable grilles on each of them. Should entire height of stud cavity be an actual steel duct now? If so, how to prevent movement, banging, etc.?