ᐅ Attic Floor Interior Insulation – Roof Starts at the Upper Floor

Hello everyone,

this has probably been explained a thousand times before, but I can’t find a clear answer.
I want to renovate and insulate the attic. That means removing the wooden paneling, taking out the old thin insulation, installing new thicker insulation, and covering it with drywall. This is no problem in the attic itself. However, the roof already starts on the upper floor. I assume I won’t be able to easily push the materials down from above. How do you usually approach this? I would prefer not to remove the sloped ceilings on the upper floor to get behind them. Insulating from the outside, meaning stripping the roof, is also not an option for now.
Can you give me some advice?

Thanks a lot.

There is also injected insulation, which might be an alternative. However, I am not sure if it can achieve as good performance as regular cavity insulation between rafters.

Hello everyone,

I recently had a roofer here who told me to remove the wooden paneling in the attic. Then I can double up the rafters all the way to the attic floor and insert additional insulation between the rafters. This means the insulation from the attic floor upwards will be thicker (20 cm (8 inches)). On the upper floor, the insulation remains only 10 cm (4 inches).
The important thing is to cut the aluminum foil on the old insulation before placing the additional insulation on top.

If anyone is facing the same issue, I just wanted to share my solution here.