If used, (for example, retrofitting a project that already has a drop ceiling in it and is not being removed), then the air above this drop must be ventilated with conditioned room air to avoid the confined trapped humid air in this area. Despite applying ventilation to this area, the ceiling and lights, insulation, supports, etc. may still be subject to hidden, trapped condensation.

Where a drop ceiling was installed and there is no vapor barrier in place between the insulation and the surface of the drop ceiling, we highly recommend either installing the proper vapor barrier or using vapor barrier (waterproof) paint.

Ensure the room is under NEGATIVE PRESSURE.