Pergola Lining

...stick some battons under your rafters:

https://www.jameshardie.com.au/produ...laboard-lining - if you want a single sheet, you will need 6mm. Go for 1200mm wide sheets as they are heavy to put up and should fit nicely with your 6 meter long pergola....if its all measured right! There are other brands that do something similar. Use some plaster glue/paste and screw in 4 screws across each batten. Use quad around the edges to finish it off.

..Floorboards can look great
..corri iron
..mini orb iron

Throw foil paper under the roof or foil backed blanket as it will limit the radiant heat coming off the roof whilst having a coldy!
..