The most common end panel that is commercially available for high tunnels, is nothing more than a heavy duty sheet, whether that be poly, woven, or fabric, with a few zippers on it. They are very easy to install and allow the entire end of the tunnel to be opened on hot summer days.
My kit tunnel came with zippered end panels, while my smaller homemade tunnel has framed ends. Framed ends add strength and stability to a tunnel, but can limit the size of equipment you can take in and out of a tunnel. Zippered panels are easy to install, and cheap (OK maybe less expensive is a better way to put it) and they allow total access to the tunnel.
The biggest disadvantage to zippered end panels is that they do not hold up in high wind areas. My tunnels are located in a field on top of a hill. The closest wind break is over 100 yards away. Wind gust during thunderstorms or blizzards routinely get over 60 Mph. Even heavy duty zippers do not last long under those conditions.
The manufacturer sent me some replacement zipper heads that I was able to use to get my end panel closed after several blowouts. The problem is that every time the zipper fails it causes a little bit more damage that allows the teeth to come apart that much easier during the next storm. Standing on a metal ladder, leaning agaist a metal framed structure, in the middle of a field, on top of a hill, durning a thunderstorm, ( can you see the picture I am trying to paint) trying to fix a panel before more damage is done, gets old pretty quick.
Durring the last storm, I lost the last zipper head and had to imrovise. The manufacturer sent me some ideas that other customers had done, but everything was for smaller tunnels and reqired drilling the end rafter.
After a lot of drawing and brain storming, I descided that I was makingit too complicated (something that I am known for). I did not want to add a lot of weight so I too a 2×4 and ripped it down the middle on a table saw. I then used tek screws with rubberized washers to attach the boards to the end panel, screwing through the nylon webbing from the zipper. For a quick fix I just used clamped the boards face to face to seal the panel back up. I am going to install a pully system that will allow the ends to be opened easily. The disatvantage to this is that the panels cannot be rolled.
I am very happy to report that I have had this repair in place for a couple of months and have had some major storms. It has held up with out a problem and I am glad that I did this modification. Once I have more time to tweak this and install the pulley system, I will post an update with more photos.
Sorry that it has been so long between post, the weeds keep me tied up…. Literally!