OK, back from the barns.
@BReeder!
OK, so I build a deck, sunk in concrete and on that we built a 2x4 frame to match the base of the greenhouse. It is anchored down to that and through and into the decking with 3 inch steel barn/out building screws every 14 inches or so.
So the door, if I stand ON the metal door frame and the flat 2x4 under it is exacty 5foot 4 inches high in it's opening.
The width of the door opening is one seeding tray and one carrying hand wide. Which means when carrying a fully loaded tray, you have to turn it 90 degrees as you pass through the opening if you want to carry it two handed. I took to carrying them like pizza boxes, from the bottom.
OC I don't stand on that using the greenhouse, I step up and over the 2x4 in the opening. I looked to see if you could cut that lower frame off, and the door rides that track when it closes as well as the top one and there is no secure lower latch on the bottom of the opening doorway frame to keep the door when swinging when shut like there is on a sliding barn door in your house or on your barn.
That said we secure the door open and shut but using a spring hand clamp on the track.
We also over did it with the metal screws on the panels, but haven't lost one yet.
We lost one of the vent panels to a windstorm as there is no place for extra clips or screws due to the design of the vent windows. so those are gator glued in place and secured with silicone caulk.
The vents I added let me keep the door closed on 30-40' sunny and cloudy days and keep the temperature around 80 with the upper vents closed. Anything abovve about 45 on a sunny day and you can hit 100 or more.
I've pegged out thermometers in there with the door open, the vents all open, including the roof at 130'. Without wind to move everything along, it just gets too hot in there. I've found it hard to control past late May, and unusable again until October, but it looses heat really fast, even with vents closed at night and will quickly match the outdoor temp. Although being covered does help with earlier frosts.
All the cracks in the decking were filled and sealed, so the floor is solid, and the white vents all have caps.
In retrospect, I would not have purchased it. With the added work and cost of the decking,concrete, etc, screws, vents etc, I could have had a small frame shed built and delivered and craigslisted some windows or built frames for vinyl panels, and the place would have been higher and wider. That's another thing.
I built a two level shelving system, closet racks and 2x4s. I can get a lot of seedling trays in there, but they have to be rotated every other day, to give the lowers enough light and the NE wall plants enough light. After a certain height, the bottom shelves are useless, and the top shelves aren't far behind that due to the slope of the roof.
OH well. Live and learn.