We used a 14’ dome for 29 years until it started to collapse last fall and I had to demolish it. It was framed with redwood 2”X2” and plywood hubs (it was a kit) Hail would shred the plastic cover in a hard hail storm so I took my router and a rabbiting bit so I could glaze it with 3/16 glass. I made hub covers with 1/8 Plexiglas circles that I heated in the oven and molded them to seal the hub joints.
One of the big problems with the dome was cooling it without roof vents. We had a fan in and fan out but it still over heated.
For this season we are using a tent like kit to start our seeds but this summer we will buy a aluminum framed glass unit probably 12 X 16
