garden shed insulation

hello everyone

ive built my own shed recently,ive now come to insulate it.
i have 1" thick jablite (polystyrene) to go inbetween the uprigthts and roof.
then to finish off with 6mm ply as the skin,basicly my question is do i need to add any air flow inbetween the runners to stop condensation?
any advice would be appreciated

thanks jon

would i ive have to make holes in the ply top or bottom or anywhere for airflow?
ive never done this before so i have no idea if i need to.
bump on this please.

ty jon

I wouldnt put any holes in it mate. Ya only need a bit of airflow in the roof.