Top plates are where the wall meets the ceiling. They leave gaps that allow air to escape into the unconditioned attic and be lost. To prevent this air loss, we want to air seal all of the top plates and any other air leakage points, such as chimneys, recessed can lights, bath fans, and utility penetrations.
The chipping on the scuttle access is a result of the wood panel absorbing moisture due to the heat and humidity in the attic. To help mitigate this in the future, the attic would need to have adequate insulation installed and the access panel would need to be insulated to resist the heat moisture impacting it.
An attic without enough insulation impacts the living space below. In the Summer, the attic is sweltering, without adequate insulation, the ceiling heats up and radiates heat into the rooms below. This makes your home harder to heat and cool.
Ducts are in the attic because there is enough space for them, but it can also make them very inefficient. In the summer your attic is HOT and it heats up everything in it, including the ductwork. Cold, conditioned air is pushed through the hot ductwork to try and cool your home. Instead, the ductwork heats up the cool conditioned air making it significantly warmer and your home is harder to cool and your HVAC runs more to try and get the home to the temperature you want. You're left with uncomfortable rooms, high energy bills, and wear and tear on your HVAC system. (The reverse is true in the winter.)
A key to making our home comfortable and energy-efficient is keeping the air we pay to heat and cool from escaping the home quickly. This Callao, VA attic has some of the most common problems that cause heat and air loss in our homes.