My original Garden Dome 3 was successful prototype. It was lifted up on brick blocks and given the Base Option for further experimentation. After 14 months several hundred pounds of weight were added for a static weight load stress test. Results were that the dome held up well. Some of the pvc Connector Hubs on the bottom began to bend slightly. One attaching screw pulled out of a strut end, so I replaced it with a longer one.

Board on lower right of this photo is warped, not bent from weight of the brick.
The thicker (sch. 80) pvc is recommended for 20 ft and larger domes, or smaller domes requiring extra strength, for cover materials other than lightweight greenhouse films or glazing. As an option, only the lower 15 Connector Hubs might be the stronger type. For maximum strength such as 30 - 40 + ft domes, the steel or aluminum Hubs are recommended.

Here are 2 photos of the dome before the weight test.

One of our clients made a 25 ft 2 x 6 Garden Dome 3 + Base Option, using the sch. 80 pvc Connector Kit. Photos