: Would have been nice to get some of that HS nylon to make the top, ( good UV
: protection I hear ), but it's a bit pricey for that I would suspect. I
: priced it for my Hoop-House and it would have been in excess of $500.00!
: :-p

Well, you don't need heat sealable nylon for a top. You can use ordinary nylon fabric (or polyester, or cotton for that matter) and then apply a water resistant, or waterproof coating.

The local Wal-Mart has bolts of close-out fabrics at $1 a yard. I can't always find it, but when they have ripstop nylon I pick up what I can and keep it for miscellaneous projects. Jo-ann and Hanover Fabrics (Minnesota Fabrics) have similar closeout materials at similar prices.

21 feet, or 7 yards, would span the hoop structure. The fabric is either 45 inches or 58-60 inches wide. I'd only go for 58-60 inch fabrics, so getting 4 panels which were each 7 yards long would cost me $28, plus sales tax.

I'd need to sew them together to make a piece 21 feet by about 18 1/2 feet, using very wide seam allowances. I'd try to space the hoops so that the seams fell directly on top of a hoop, and the excess fabric from the seam allowance fell on either side of the pvc pipe. Then, I could punch holes in the selvedge edge of the fabric, insert grommets and lace it up around the PVC pipe. Or, I could forget the grommets and holes, and do a fairly quick and loose hand sewing job. Or, I could create "pockets" from these seams and insert the PVC pipes, which would be held in place. Such pockets would let the fabric serve as a brace, too.

Making a pocket for the PVC tube in the shape of a wide hem at each end would give you a neat and solid way to secure the ends of the fabric to your hoop structure.

Waterproofing the fabric would be a matter of applying a coating which sealed the fabric. You could paint on a urethane or polyurethane, or a cheap latex paint. Not much different than sealing a skin-on-frame's skin, but it doesn't need to be as good a job.

Even if the fabric is NOT coated, surface tension of the water will keep summer rain water from penetrating the stretched fabric for quite a while, and the hoop shape will cause most drips to flow along the inner surface of the fabric. During the winter this works even better. Snow falls off the sides before it can melt through, so you really only need to paint the very top.

You can use plastic or more fabric for the ends.

Maybe you could get that fabric in a nice bright rehd

PGJ