*sigh*

The HFGH is tempting but when I see the up close pictures I can see that it is built the same way as a GH I used to have. Sold it a few years back. It was 8X10 and painted white with glass. The structure is identical though. As for heating in this area.. zone 5 you would have to cover it with a inflated double layer of poly. The reason is, the aluminum rafters conduct the cold into the greenhouse and you will have a heavy frost and ice buildup on the inside of the house. I am considering a new GH but it will be constructed differently with caps that will cover the rafters. BC greenhouses has some nice units, not at HFGH prices. You get what you pay for. In this area the HFGH will not stand the heavy snow nor the -20 degree temps in the winter months. It will cost a fortune to heat if you can heep it heated.

Don't get me wrong... I wish I still had my green house however it was expensive to heat and lots of work covering every fall. Also had to be on the watch for heavy snow loads.

BTW I am on the NH MA border...

Pappa How do you expect to save 85%? Not a retorical question. Are you thinking of manufacturing g/h's?
You seem to be fishing.

Please respond with:
- The size of your greenhouse (brand too?)

24ft x 14ft (home built)

- Your cost (and when you bought it)

$1000 and aquired from 2002 to now.

- What your average heating bill is.

Um... trick question... My heating (as in pure heat) is zero.

- Your Zone.

4b

- how much would you pay for the same sized GH with the above qualities?

Well, as to the reducing my heating bill by 85% then as it is zero then reducing it would not really be a probmem.

As to "Glazing is crystal clear and has a 20+ year lifespan" well, I just went from cheap construction plastic that has a "lifespan" of 6 months or so to the professional stuff that will last four years.

Will it last 4 years?.........

NO WAY!!!!! It is already bust, due to the unusual climate we have here.

If you can sell me the "Glazing is crystal clear and has a 20+ year lifespan" for $1000 that covers my 24x14 and it will last 20 years here then a check will be in the mail. Don't bother sending the frame.

tominnh: howdy neighbor. "a fortune to heat...". yep. That's why i am looking for alternatives. Hopefully i have found one.

Mylu: 85% savings is due to R-24 walls and R-30 roof. Sort of fishing. Only half serious until i finish and test. If everything works... and i had enough fun doing it, then i start fishing.

Chris In Iowa: We chatted before if memory serves me. Last I heard you were thinking of shutting down in the winter. Is that why you have zero heating?. The 20+ year glazing is a conservative estimate. They expect 30. Downside is expense and size.

It's 3 - 5 x more expensive than poly. I think i calculated a cost for my GH of $2500 vs $500 for poly.

Size, it's only available in rolls 52" wide. I have been searching for a US manufacturer for 3 years and finally found one not too far from me in Mass. It probably would work for a woodframe GH with 4' spacing between frames - go up and over the GH instead of lengthwise. I have to find or design a system to run on each rib (i have a galv. pipe frame) that i can use to attach the film. What exists now is either too expensive (aluminum wiresnaps) or doesn't last long enough (PVC type channel locks) to equal the lifespan of the film.

Poppa

So the covering is a "film"

What kills my greenhouse every time is the wind, not the wind as such but the crap that hits it in a high wind. (corn stalks usually)

Yes, I KNOW I should use polycarbonate. I am going to save all my money and buy some one day.

Will this film you found survive an impact from the sharp edge of a chunk of an asphalt shingle traveling at 90mph?

Tuflite IV is tuff but it failed that test.

(supporting data, the offending part of the shingle is trapped in the double layer of poly. It measures one inch by two inches. I know the wind speed was 80-90mph because that is what the doohicky on the power company cherry picker truck said it was when the nice men came to try to get the power lines untangled. Oh.. they sorted the power out when the wind died down, they ain't stupid!!!!)

To end on a good note, I still have a functional greenhouse. I just lost the advantages of an inflated double layer of poly.

What is the film? tedlar? dureflex? pvc? diamond? I've been trying to track down any of those in clear with a suitable price and lifespan. However nobody seems to make clear tedlar any more; a friend said dureflex died in the sun and was no use; pvc is quite expensive because it needs to be very thick; nobody sells diamond film in big enough sheets.

diamond would be the best, being 100% UV transparent (thus not affected by it), by far the highest tensile strength (something like 200GPa), basically inert and very light. However the biggest stuff I can find is still only 10cm wide.

So what is your film? Do the manufacturers money back guarantee the film for 20 years? Will they still be in business in 10 when it fails? Why aren't the commercial growers already using it?

For supporting the film I would wrap the film around some smooth edged hardwood and form a compression joint with bolts and another bit of wood. If the hardwood is inside the film and no water can get in it would easily last 20 years.

If the film is strong enough, perhaps you don't a frame, just an airlock and pressure activated blower with a check valve. Just inflate the whole structure.