I bought the fittings from a tarp company and used black iron fire sprinkler pipe making a complete skeleton including connecting it to each side on the ground. I did put horizontal pipe midway on the sides as that is what I bungee the tarp to, giving me great coverage from the sun and elements. I put pipe gussets or angle braces in the corners.
I should say that I used top rail fence pipe for the ceiling/roof trusses as it is lighter in weight.
I used augers to secure it to the ground.
I haven't taken it down since I put it up in 2009. It has survived all types of weather, including hurricane Irma. Every few years I have to replace the tarp (and bungees) as this central FL sun will deteriorate it.
This is a cheap, yet secure canopy that will give a bit in the wind. (The secret to withstanding strong wind...)
Let me know if you don't follow my design as I can detail it more or take pictures. And I have sources for the parts if needed.
Good luck!
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