A double furring strip is the cheapest and easiest, if you have wood baseboards. I wouldn't use just the wiggle wire strip for they hip board. I have a treated 2 by 6 for my hip boards and the wiggle wire strip is bolted to that. The previous owner lost the plastic 2 times with just the wiggle wire strip and that was one of the reasons he quit using the building, his loss my gain!

i think wiggle wire and channels should be used. screw the channels to the baseboard and then move them to the hip board when you do that part. if you use just the channel for the hip board you need to use the double channel. if you mount the channel to wood the single will do. roll down sides can be used but are more involved to install. to keep the roll up sides down you use antibillow ropes or something similar and wiggle wire the ends closed. it also helps to have a heavy roller for the roll up sides, that is using steel tubing instead of pvc.
my experience with not using the more costly systems means you spend time maintaining and rescuing your structure at the expense of not spending time attending to the stuff you want to sell.

I have steel tubing - the tunnel used to be 150ft long with 1 ridgepole, when we put it up it became 65ft. I can buy more for other side.

But 2 conflicting opinions from experts - for now, trying to avoid putting holes in plastic since this isn't final configuration. Does the double furring strip put holes in it? I don't see how to sandwich plastic between wood w/o putting holes in.

I had read that wiggle wire can put stress on plastic and weaken it, if not put holes in (right away), but Jaderloon said they never heard of such a thing. I have to order tomorrow time is running out.

What do you mean by "if you use just the channel for the hip board you need to use the double channel. if you mount the channel to wood the single will do" - did you mean that if I permanently attach the top of the roll-up side to the wooden hipboard then all I need is channel on hipboard for the top piece of plastic?

I use 2x2 boards on the straight runs and wiggle wire on curves.

The arsenate in treated lumber is corrosive to greenhouse plastic. It's much worse with new lumber. I use untreated 2x2s and paint them with white latex paint, and I also paint the baseboard where they will be attached.

when you use the double furring strip you use screws to hold the 2 strips together and to keep the film between them so the screw passes through one strip and then the film and then the other strip. then the force to hold the film comes from the screws and the holes made by the screws become larger over time.
i have a rimol high tunnel and the hip boards are not wood but just a double channel and it holds just fine. a single channel is more flexible and as jay said can fail. on the 3 other tunnels i have i used 1x4's for the hip boards with single channel and that works well.
my roll up sides are not a separate piece of film from the film that covers the structure.

Randy - so your double channel is attached directly to the hoops, no wooden (or composite lumber) hipboard? How is the plastic attached to the single channel and hipboard? Just tuck a fold of the continuous sheet of film into the channel to hold it, then let the rest fall down the side to the steel tubing which rolls it up?

Thinking about it, I can see that would work, but the wiggle wire doesn't wiggle out of the channel when you put the sides up and down multiple times (would be a problem whether single or double channel, but with double channel at least it's just the side that may come off, not the whole thing)? There must be a reason why people use double channel mounted on hipboards?

Randy - can you post pix of your 2 different channels/hipboards? I'm also wondering how to hold the pipe for the roll-up sides up - bungies strong enough or do you have half pipe clamps mounted on the ends to slip the ends of the pipe into (and bungie the middle to something so it doesn't sag)?

If double channel is stiff enough to mount directly to hoops, I could do that NOW. I mean, I've got to mount it somewhere, might as well do it in final location. I just didn't want to take the time to buy lumber for hipboards this month and put them up before putting channel up. But long-term plan was to mount rain gutters on the hipboards too and try to put rain barrels out there so maybe I should stick to original plan.

Thanks Cole, the baseboards are very old treated lumber, I don't know if that will cause problems with the film over the next couple of months. I do have some cypress I was going to use for hipboards but I used the better pieces for raised beds (8-10" wide) rather than rip them down so I will have to find something else for hipboards. May have to be 8ft lengths of PT 2x4 (1x4?) to allow room for gutters, painted with latex (not oil?)

The devil is in the details...

i found this video showing the double channel.
there's a whole series of videos showing how they erected a rimol greenhouse and although thats not what you have many of the methods can be adapted to your needs.
i have pics of using the single channel on one of my houses and i think they are posted in some thread here. its not real recent though. i will try to get to posting them later.

Here is a link that might be useful: double channel hip board

It's important for the life of the plastic to use two layers of plastic with the wiggle wire. At the bottom and edges I just fold the plastic over but at the hip board I cut strips from scraps.

OMG, I'm doing it all backwards! Cross connectors are on their way, I don't know how we're going to get the ridgepole on with the tomato plants nearly touching the top now (there's going to be some casualties) but I had to get them planted. I thought I'd ordered the connectors in early June but they never shipped. The soil was in the middle anyway by then, so unless I give up this year and then move a ton (literally? 60ftx4ftx2ft) of dirt next year, I can't get a solid surface to stand on in the middle, we're going to have to reach in from the aisle(s) 2ft to the side.

Thanks for the tip kelise.

Jaderloon doesn't seem to have double channel for wiggle wire. They have "2 layer" Kwic Klip system but I don't know if that's for 2 layers (inflated) of plastic in 1 position or whether it's for top and sides.

Rimol system looks nice, no hipboard required but as I said if I want to add rain gutters I'm going to need hipboards.

Anyone have any recommendations on where to buy wiggle wire and channel if I want double channel?