If you order one piece and cut it into three, top and two ends, each of the three pieces needs about a foot excess on each end. So total length needs to be 32ft + twice the height + at least 6ft to allow 1ft excess on each end of three pieces.

My biggest hint would be don't put it on too tight if it's warm when you apply. Poly shrinks and swells more with changes in temperature than you might think. I put mine on too tight last time and it caused issues later on.

What is your fastening system?

Getting the film to lay smooth, without overlaps, requires that you keep it pulled squarely and evenly while attaching (one reason why you should give yourself 3 ft. overlap at the ends until the framework is fully covered securely). It works best if you have two or more people to hold the film as it is secured. This process is just one more reason why I like the wire-lock system to secure the film- you can easily undo a section and re-allign it.

All that being said if you plan on roll-up sides I often will replace that roll-up curtain after a few years b/c it is more likely to be worn thru from repeated fastening at the corners. There are ways to remedy those problems but that is a whole new topic for discussion.

How tightly you fasten the film will depend on wether or not you inflate 2 layers. You should allow a slight amount of slack if you do inflate.

I would suggest that you cut seperate sheets for the ends to avoid "Bunching". With wirelock you can easily attach a second wiggle wire into the same channel over the end film after the arches are covered. Some might cover the ends first and then install the main cover, depending on which you think you will be replacing first.

If you use the plastic poly clamps that snap over your pipe, put a screw in them for extra strength.

I've tried both of these methods and can't see any advantage over the wire-loc system, especially if you are short on help to attach or reattach.

http://i186.photobucket.com/albums/x252/dotheopposite/1109111532_zps22 76f8ff.jpg

http://i186.photobucket.com/albums/x252/dotheopposite/1128121412_zps7a 486835.jpg

My greenhouse site is in an open field and exposed to high winds, so strength is very important to me. The second pic shows the decking board wrapped over 4x4 posts set in concrete. It's probably overkill, but I like it anyway.

The decking board also allows me to bend the wiggle wire channel without having to put cuts in the back of it. A screw every few inches, starting at one end, will wrap it nicely. It's much easier material to work with, for me at least. Screws don't spin out and I don't have to worry about weakening a metal end hoop with screw holes.

I like wiggle wire for curves, but I'm going to use 2x2 boards for attaching the plastic to the hip boards on the side.

Also I've trimmed mine too close after instulation. Then didn't have enough to reattach after patching holes.

Those plastic dementions appear OK Quadcab. I'm just a little more concerned about length of your main cover. Leave yourself a little extra to pull on and allow for less than perfect allignment. Trimming is just easier than taking hours to properly allign. That being said, I did install a bubblewrap section on my smallest GH, a 40' long structure, that was exactly 40' long. It was the hardest film installation I ever did b/c it was very difficult to stretch the bubblewrap and with an inner and outer 6 mil film I could only use 1 wiggle wire. I resorted to alternate clamping 3' sections between 2 wood strips with 2 sets of vicegrips, pulling to give just enought coverage to insert the wigglewire. There are easier ways to handle film installation than that.