You can actually order replacements cheaply from Harbor Freight, just be very specific and prepare to be patient. Also, I recall another poster used the thicker panels and had no problem with them fitting. Do get extra clips and add them to all of the panels to keep any more from getting away--the kit is pretty skimpy on clips.

Alia

I am in the same boat - I have an 8x10 HFGH greenhouse that lost a roof panel over the winter... :( Does anyone happen to have the replacement number for the panels to order from Harbor Freight? I can't seem to locate my manual/sheet that may or may not have replacement part numbers on it. Of course I am going to have to buy a ton of clips, too, so many panels blew off this year (luckily only one panel blew away completely). I knew I should have waited until this spring to put up the greenhouse instead of doing it last summer when I didn't have a chance to actually use it! :)

Thanks!
Stacy

You can also do a Google search -- twinwall +4mm -- and get thousands of hits.

The 6mm is only 80 thousand thicker than 4mm so it will fit but it don't matter how many clips you put on it you will still lose panels until you put screws in the center.
When the wind blows into the GH the panels will bow outward and this makes them shorter so they pull out from under the clips.
I used #10 self tapping screws with a neoprene washer and put them in all the cross bracing in the center of the panel this will keep them from bowing out.

Look at the link below. Sundance Supply has lots of info on polycarbonate panels, how to install, etc.

Here is a link that might be useful: Sundance Supply

I lost 2 panels before I posted a fix earlier this site. I ended up buying a lexan panel at Lowes, that are thinner and way more costly than the original. Since it was only a temp fix and had to be done, I paid the price. After drilling 1/8" holes 1 foot from the bottom and top (on the vertical supports), I threaded a 12.5 gauge galvanized wire (TSC) thru the holes in a horizontal fashion. Curled the ends over at each corner. Repeated the procedure for the front, back and top sides. Used a single self tapping screw in the vent window. Winds since then have not bothered the HFGH.

I checked the prices for replacement panels, and if you order nearly any quanity, the base price is high and then you have to add in extra shipping and possibly a crate charge, which makes the whole deal too much for each panel. Figuring everything all together, it is just cheaper to first secure the panels with the method I mentioned above. If you have lost a panel(s), then order another kit when they are on sale. My first HFGH was $299 + $20 Ship. The second one was $329 + $62 to ship. That is still cheaper than ordering any panels from anyone. Plus I have extra parts forever, to - add-on, repair, replace, etc.

As far as a base for my unit. I used 2 ea 4x4's PT stacked. Used the PT wood to allow the base to be leveled, with 1 to 1.5 PT showing above ground. At the corners and mid-long side, I sank a 4x4 PT down 2 feet in the ground, anchored with 1 bag of concrete in each of the 6 holes. All the base is bolted together with carrage bolts. On top of the base plate, I screwed in a 2"x7'x1/4" Poly Trim that is used around garage overhead doors. Use a sealer between the poly trim and the PT wood to stop leaks. It won't rot. Then I used stainless steel screws (2"#10) every 6 inches to fix the alum base to the poly trim and PT 4x4's. Everything else is per HFGH Instructions. Then I topped it off with the reinforcement I mentioned above.

In the center of this frame, I tamped Stone paver sand and rock base, topped with 24"x24"x2" colored concrete blocks. There is a 60W Solar Panel 15 feet away that runs the fan in the greenhouse to help keep it cooler. It helps.

I HAVE HAD MY HFGH FOR FOUR YEARS NOW AND HAVE NEVER LOST A PANEL. I LIVE IN NEW ENGLAND AND IT GETS REALLY COLD AND WINDY IN THE WINTER. IT HAS ACTUALLY SURVIVED (INTACT) MANY NOR' EASTERS. THAT IS REALLY SAYING SOMETHING. I THINK WHAT MAY HAVE SAVED LOSS OF PANELS WAS SEALING ALL OF THE SEAMS WITH A CLEAR POLYMER GROUTING THAT I BOUGHT AT HOME DEPOT WHEN I FIRST CONSTRUCTED IT. I USED THE STANDARD LONG GROUTING GUN AND IT WENT PRETTY QUICKLY.

JUST A THOUGHT......BUT IT REALLY DOES WORK.

hello,

I need help....I have the HFGH greenhouse for four years. It was a wonderful buy........but, when I erected it I peeled the protective film from the panels as I was supposed to. I thought that I got them all, but only now I realized that I missed several. The reason I think that after four years I am just now noticing is that the film as broken down and deteriorated. My problem is this.....How do I get rid of this residue. Has anyone had this experience? I have tried every means known to man, but I cannot get rid of it?

Gemplers!!!! Great price on paneling and the only reasonable shipping I have found.