Attic Insulation - Ceiling Insulation
The insulation on the flat should prevent heat from radiating down into the space below in the summer months. However, the batt fiberglass in this space is not enough to keep the space comfortable. There are hundreds of holes connecting the living and attic spaces allowing air to escape that need to be sealed. In addition, fiberglass is only effective when enclosed on all sides, currently, it's acting as an air filter for escaping air.