johnsnower

Jpeg attached maybe that makes it clearer?

Hi sorry, its a cellar but the ceiling of the cellar.

Im looking to insulate the ceiling of the loft between the joists. The room is 4 x 4m has some airbricks in the walls (2 external with air bricks) and one has a window in which i leave slightly open for airflow. So the question is how best to insulate? Im guessing its PIR, if so any idea on depth? Do i push it right to the floorboards? Can i plastboard it out when done or best leave the joists open to breathe/airflow? Thanks