NOTES ON HOOP INSTALLATION
When placing the hoops into the correct width ground posts, the hoops should be about 12” wider than the ground posts. After you place one side of the hoop in one side of the ground posts a partner pushes in and sets the hoop in the other ground post.
This "spring loading" of the hoops give them their strength and stiffen up the arch. Don’t push the hoops in as far as you can, you will adjust the height before you install the hoop to ground post bolts.
When all of the hoops are installed it is very common for them to need initial leveling and plumbing. At this point it is best to have the keenest eye among you on a step ladder with eyes level with the top of the hoop.
“Eyeballing” the hoops all the way down by pushing hoops in or side to side will get you close but do not expect them to be perfect. They all straighten up when you begin installing the hip boards, baseboards, and ridge poles.
The following statement is true for the entire build but mostly comes into play at this stage. Because all farms, skill levels, and tolerances are variable, hoop houses are designed to have some play in them.
These are not Swiss watches that are precise engineering marvels. Hoop houses are rarely perfectly square, plumb or level. Do the very best you can, occasionally re-do mistakes when your gut tells you.
Once the plastic is on tight all small miscalculations go away. This isn't permission to cut corners or skip steps. It's more of an "you'll be ok if you are off a tad".
Learning to take farming tasks in stride now will do wonders for your agricultural career long term.