We bought a prefabricated house a few years ago. It has a first floor and an attic as living space. Above that is the peaked roof at about standing height.
The insulation is currently installed on the top ceiling of the attic. The peak floor is not insulated, and has only a foil under the tiles (probably trickle protection). I would now like to lay OSB boards on the top floor. To do this, I have a lathing before to allow air circulation under the plates to the insulation.
When checking the structure of the insulation, I came across the following. The ceiling of the attic is gypsum board, then up follows a vapor barrier (I assume because it is metal-coated paper) and on top lies the insulation wool. Now the question arises whether I can insulate the attic and if so, how would the structure or a connection to the vapor barrier be made? Do I have to open and fold up the roof insulation and barrier for this?