Illustration of how to board a traditional roof
1. This attic had just a thin layer of 2cm insulation, no wonder it's chilling
2. Put base layer insulation between original joists
3. Fix additional perpendicular joists to original structure, then put 2nd layer of insulation. Now the roof prevents heat loss with 20cm insulation!
4. Boarding, it's harsh crawling at corners!
FYI insulation is irritating, you don't want to scratch yourself after work.
