update, 21 Feb:
Turns out the HOA president of our neighborhood is a civil/geotechnical engineer who enjoys gardening. I met with him yesterday and we are working on a set of plans to appease the folks down at city hall.
I also did quite a bit of research into hoop house structures and found the kits you buy on
Rimol or
Farmtek are made from 1-5/8" diameter 14 gauge (0.085" wall thickness) galvanized steel tubing.
The Johnny Seeds hoop bender manual that I ordered/received says to use 1-3/8" galvanized tubing commonly found in hardware stores chainlink fence section. Its residential grade top rail and it's either 17 or 18 gauge depending on the store. I would imagine that JohnnySeeds is marketing to the DIY'er who doesn't have to deal with building code at City Hall. For my purposes, this would never fly so mods. will be necessary.
I called a few chainlink fence companies locally and they were well aware of the heavier 14 gauge "commercial grade" chain link fence tubing and can get via special order.
So, long story longer, the engineer is comfortable with me replicating the Rimol or Farmtek commercial greenhouse frames that use the 1-5/8" 14 gauge tubing that I can special order from fence company. I will also need a cross brace and additional truss supports, everything 14 ga.
I'm updating my plans for engineer review/stamp today so I'll upload here when done.