Hello Frosty,
yes I have some experiences. I don’t know how much snow you get in winter time but my aviaries were still ok when I had 20 cm snow on top. If I had that much on top I were shake it down to avoid an overload.
Over the whole area I made steel crossing with 3x3 m and on all cross points were a pillar. In between the crossings a tensioned steel wire were supporting the covering. For covering I used a 50x50 mm wire mesh. But you can also use a net. But to remove the snow in winter it is easier with a wire mash and it is also more save for the peas because they cannot be cached up. If you are living in an area with a lot of snow I would recommend to make the steel crossing a little bit closer 2.5x2.5 m. When you look on the picture in post 27 (of Pfauenfreund in this thread) he has a similar design. On the picture you can see the steel crossing. On his web page he has a detailed description of his design (follow this link
http://www.pfauenfarm.de/Home-English/The-Peafowl/Husbandry-PM/Aviary-PM/aviary-pm.html).
After you read his instruction and you still have some questions, don’t hesitate to contact me again.
Regards
PeaChecker