The first day we put up our green house we hadn't finished putting earth back over the plastic to hold it. There was a storm in the night. Next morning it had ripped off the plastic, taken out two of the poles and broken a third.I'll have another look at your coop later.
Securing the tarpaulin is where I'm short on experience and ideas. I've found one that is affordable with eyelet rivits every 6 inches at a fixed size which if fitted would only cover say 60% of the hoop. I could stitch that to the weldmesh with line wire. The stitch won't give but the eyelets might tear out.
Having the tarpaulin rip loose, I and the chickens can cope with. It would just blow onto the main run fence. Finding out that the tarpaulin had held but ripped the hoop structure off the ground and maybe torn away from the coop itself is not what I'm after. Best of all is if it all just stayed put.
I've done the coop's blown over bit a few times in the past. I can't be doing with the drama. Hurt chickens possibly. Coop needs sorting out and quickly. You've been up most of the night checking that the chickens haven't flown off with the coop. Then it happens, you've just managed an hours sleep between 5am and 6am and gone out to see in the coming daylight and a coops on its back with busted panels and some very frightened chickens inside if the roof stayed on.
We also had some bad experience with the tarp protecting the old houses when the roof was down.
If you tie the tarp to the main structure I would say anchor the main structure by tying solid strings to cinder blocks all around. Unless it's completely hermetic and no air gets in a tarp will always act as a sail and pull away anything.
I would prefer a floor I could sweep and mop but I've got carpet instead. I recently bought a vacum cleaner. I don't think I'll be getting one of those robo vacs.
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