46 CFR § 32.56-20
Insulation of exterior boundaries: Superstructures and deckhouses—T/ALL
April 15, 2021
The following exterior boundaries of superstructures and deckhouses that contain accommodation, service, and control spaces, except wheelhouses, must be insulated to “A-60” Class:
(a) The exterior boundaries that face the cargo area.
(b) The portion of the exterior bulkheads and decks within 3 meters (10 feet) of these boundaries.