That thought has been a concern of mine since the get go, especially with a brand new tunnel. Plastic blows off three years down the road, meh. Three weeks after completion OMG.
I'm not doing very weatherproof components just for the humidity inside a tunnel. I'm doing it for possible sprinkler use and in the case that the plastic is in a tree and I can't replace it until the wind dies down in a week or 3. LOL
Little cool down this weekend so I'll get started with track at least. Work on the arches where I have to bend the track to the arch.
Godspeed, LOL! :)