The doors are placed on the ends to line up with the necessary center aisle in most cases. Putting a door on the sides would reduce the bench/growing space, unless you were planning an area at one end to have no plants anyway. Greenhouse doors can easily be made of wood framed polycarbonate panels, with little light restriction.

Thanks for the reply cuestaroble... that was about the only reason i could come up with as well. Since i am considering moveable benches, that probably won't be much of an issue for me.

Poppa

The idea of anything other than end doors on a arch greenhouse really complicates all sorts of things. My main reason for doors on the ends is the permanent nature of the ends and the relative temporary (3-5 year)lifespan of the film covering. Just thinking about the complexities of framing a door into the sloping side and then cutting plastic to fit around it every few years is a negetive aspect.

Light blocked at the ends is a minor consideration. I have not ever noticed a difference between end and interior grown plants in a solid end structure. Cuestaroble is correct in that often polycarbonate is used on the end framework. The factory framed doors are often squarestock metal so they are lightweight and block little light.

I've framed ends with everything imaginable from sliding glass doors, windows, used screen doors and just plain plywood. My advise is to stay frexible in your end framing. You might want to add another exhaust fan or intake louver or even just add an extra door for convenience sake. Then again you might want a Penn State High tunnel end that almost the entire end is hinged to lift to allow a tractor to drive straight through the structure.

Thanks for the things to think about bmoser....

As far as the complexities of framing into the sloped side.... what gave me the idea was as i was looking at the frame, i realized that if i dropped straight down from one of the purlings spanning two ribs, i got a nice square opening that only invades into the GH by a foot or two. The complexity of framing the entry would not be anything more than adding a ~flat dormer to a roof.

The concern i have about light is that i plan to grow through the winter. Not sure what i can grow yet, but i have had several growers tell me that every drop of light is important for winter growing, even reflected light from the north side, so they recommended against insulating the north side. Any input is welcome.

The point you made about cutting plastic around the doors was exactly one reason i thought it might be better to have one centrally loacated door than two on the ends. Actually i have been trying to find a supplier of greenhouse sized sheets of tefzel so i wouldn't need to replace them at all (projected 20 year plus life span and clearer than anything else out there). I have only managed to find 50" rolls so far, but i think i want to play a bit before committing to so much work and cost (expensive!)

So much to think about - lol - i tend to gather more data than i can posiibly use, then throw it all out and go with what fits as i build it. *grin*

Thanks for the input!

Poppa

Poppa,
Of course you could go the route I took, down the yellow brick road, and end up with "THE GH FROM HELL". You are doing the right thing, plan, which I did not do enough of. Soon, very soon I will start relating the tale and will use the ag0-985 thingum like hfgh, only mine will be
TGHFH LOL grin, time for another beer.

1eyedJack and the Dawg

Poppa,
Can you tell me where you were able to find a supplier for Tefzel? I had contacted my local plastic supplier that even listed Tefzel on their website, but the salesman told me he had never heard of it, and he didn't know why it was listed. I was told he would look into it and call me back. That was last year now :(
Thanks,
Paul

Paul, just saw your reply. I checked my old emails and couldn't find it. I'll do a more thorough search later tonight. I believe it was a company in eastern Massachusetts near Boston. They were kind enough to send me some samples of varying thicknesses so i am sure i am not dreaming.

Rob

The company is AMERICAN DURAFILM CO., INC.
They had 52" rolls at the time.

Good luck!
ROb

Thanks Rob!