This guide recommends considerations when designing the interface between a fire door (closure penetration) in proprietary gypsum separation walls. The guide discusses three scenarios. These are performance under an extreme fire; performance under a limited fire; and performance under normal (non-fire) service conditions that may include high wind or high seismic event. The guidance is intended to direct a designer’s attention to potential issues that might impact the performance of a closure penetration in a gypsum separation wall that use a thick wood-based sheathing (i.e. combustible) for carrying the weight of the fire door assembly.