Good thinking Paul. Probably saved me a big headache down the line. Thanks.

What do you think about methods of heating the hoophouse, and daytime/nighttime temperature fluctuation on curing epoxy, besides that I should plan to allow temp to fall as epoxy cures? Does outgassing become less of an issue the more cured it becomes? What will be key to making this work over the next few months, where outside temps are going to average 10-30° below minimum curing temps? Should I just wait til spring to do this project?

: Return the plastic.

: Working with 2 10-foot PVC pipes joined together you'll have a 20 foot plus
: about 1 inch distance from end to end. That is the span you need to cover.
: If you use 10 foot wide material you can cut a piece 21 to 22 feet long
: for every 9 to 10 feet of length for your hoop house. The seam between
: those pieces will be parallel to the hoops. OR, you can cut two pieces of
: plastic sheet the lenght of your hoop house, and join them so the seam
: runs along the ridge, going the length of the oop house. I think that is
: the least desireable way to go.

: Seams in the 10 foot polyethylene are iffy. If you do any overlap your
: combined width is going to be 19 feet and 6 inches, or so. Duct tape will
: hold for a while, but exposure to the elements will loosen its grip in a
: month or less. There are some special tapes for joining polyethylene, but
: find these first (if you can).

: You have a simple option, though. Look for plastic which is 20 feet wide, or
: better, 25 feet wide. Wal-Mart near me had 4 mil plastic in a 20x25 size
: for about $7. You can cover the hoop house without seams with this wider
: material.

: I fastened the ends of my PVC pipe to 2x4's, using "u" shaped
: galvanized conduit holders, and stuffed a little over 2 feet of plastic
: under the 2x4 on each side of the building. The weight of the 2x4 held the
: plastic down, and I could tug on it, here and there,to straighten it. The
: plans I had called for using a stapler to secure the excess plastic to the
: 2x4. I didn't bother, but it might be a nice idea.

: The hoops just form a tunnel. You need to close the ends. Frame the ends with
: 1x4 or 2x4 lumber and staple plastic over this. Buy a couple of smaller
: pieces of plastic for this. 9x12 sheets should be just fine, and
: inexpensive. You can also staple the ends of your plastic "roof"
: to this to secure them.

: The hoop structure is weakest when forces are applied along its length. A
: good push along the ridge can bend all the hoops at once. Counter this by
: working in some guy lines. It doesn't take much, but placing them so they
: are out of the way can be a challenge. You might weave them among the
: poles and run them from the ridge down to the 2x4 base. Or, put a few
: outside the building. If you use external guy lines, tie them to stakes,
: not trees.

: PGJ