If you don't have one, an inexpensive trail camera is a great buy. Even if you don't need it now, it's good to know what predators are around and what they're up to.
I'm pretty ignorant on this ... but the pictures at Cackle suggest that darker colors are better.
https://www.cacklehatchery.com/product/cinnamon-queens/
I'd suggest taking a look at @Rancid Crbtree 's build.
https://www.backyardchickens.com/threads/my-coop-design-and-build-blog.1612130/page-5
You'll find a similar style run as what you have that got completely overhauled into a more solid structure. That's more than most people would try to...
A lot depends on what you coop is like. Most coops get pretty big. For that weight to sit properly, the foundation needs to level. Otherwise, things will start to shift and crack. Pictures of the ground, coop/plans might help.
Yes, things are very stable. I have the door frame strapped/screwed to the top of the arch. Plus, I cut off the bottom horizontal line of the cattle panel so that the vertical pieces spike 4-6" into the ground.
To not use a base, I got the idea from Blooie's run...
My hoop run has no base. It's held in place only by the T-posts. I used cattle panel for (bottom section of) the other walls as well. The door frame is just 1x4's sandwiching the cattle panel framing. They're up off the ground to reduce rotting.
In some ways, cattle panel is very flexible...
:welcome Glad to have you with us. This thread is very old. Most people haven't been around in about 10 years. Those that are already built their coops.
This is all i could find: (and it doesn't strike me as secure)
https://www.backyardchickens.com/forum/uploads/90403_inside_run.jpg
https://www.backyardchickens.com/articles/the-coop-de-grass.48524/
I wonder if you could setup something like electric fencing around gaps in the opening to keep...
After seeing Mel Gibson's The Passion of the Christ where a bird pecked out an eye of one of the criminals on the cross, I would never let a bird near my face. I don't let my children get their faces close to the chickens either.
Overkill, I'm sure. But, I also don't see a benefit to opening...
I have a small coop and use all Sweet PDZ as the flooring. It's like a full size poop board. Zero concerns in the coop ... and lots of advantages. I've never put it in the run, as that's all wood chips.... not sure how much you would need in the run to be effective. I almost never have flies...
I had to look up Polyface:
Interestingly enough, Mercola just had a post today attached for your convenience):
Diverse Agriculture Benefits People and the Environment at the Same Time