The previous owner was partially isolated. Unfortunately only a 3cm thick glass wool, what in my opinion is insufficient, and is also wrong. I mean, a 5cm PU insulation to apply and then a 2-4 cm thick stone/glass wool muster. So, the old insulation had to leave first. The Dack was insulated with styrofoam, which I also removed.

Of course with protective clothing, otherwise jadhav's everywhere.