When I added the room addition, we got rid of a perfectly working good looking patio door. We were giving it away for free, as well as 5 large double pane windows, but no takers. I had no plans of building any greenhouse structure at that time.

So we got rid of perfectly working windows, patio door, bring them to the dump and paid $12 at the landfill, GRRRRR!

Here’s a picture of the progress and the door. I now have a bad fan to send back. Two blades are out of balance and 7/8” bent. It shakes the whole house. I told them that I would change the fan blade but they want the whole thing sent back.
Karl

http://img517.imageshack.us/img517/3475/dscn1823cm7.jpg

Karl,

If you can find a way to double the layer of the film and having a small air gap in between the next layer, that would be very efficient heat conservation.

One way that I could think of is cutting 1/2" wide but very long strips of bubble-wrap material taping them at regular intervals, then place the next layer of polyehtylene film over.

Double layer is always better than single if you can trap air in between. It will be magnitude of difference.

Regards,

Joe

Great job Karl.

Karl, you workmanship is very nice - good job. As Joe advises, double poly is a great heat saver. My greenhouse is covered with double polyethylene air inflated with a 2 inch air space between the two layers. It does save on the heat bill, especially in Colorado winters. Greenhouse suppliers market a two part lock cap assembly (male and female) that is very easy to a attach to a greenhouse and is guaranteed to hold the double layer film firm to the greenhouse, even in 100 MPH wind. I never have had a problem. Lock Cap are quite easy to find, just about every commercial greenhouse manufacture offers them. I purchased my greenhouse from Nexus Corporation. I bought their Columbine model. You can buy the poly lock cap from them. If your interest you can telephone them. I don't believe they have a minimum order on parts. Again, very nice workmanship. - Millet

http://www.nexuscorp.com/

If you look closer you can see that I already have the poly channel in place over the arches, it will accept 2 wiggle wires and up to four layers of 6 mil poly. I just have not decided to go with the double layer. Please take a look at my climate again, maybe you are right and it couldn’t hurt to have except for the extra expense of the poly and air inflator pump. I am not opposed to using a double sheet, because I really think that it doesn’t get cold enough here.
Thanks for the advice.
Karl

I used this 8 Foot Polylock Track from B& T Growers
These Springlock fasteners are made of high quality aluminum. These ... track to your greenhouse, tuck the plastic into the grove and insert the wiggle wire (must be purchased separately) and your done!! No more worrying about ... loose. Up to four layers of 6 millimeter plastic, along with double wiggle wires, will fit into the Polylock Track

http://www.growersupply.com/

Yes, I have also seen the wiggle wire application. When I wrote the above post, I thought about the somewhat limited extent of savings that double poly would offer a greenhouse located in Southern Louisiana. - Millet

Thanks for the compliments, and it’s finally finished. I don’t know how I will ever fill this thing with plants? I bet you heard that one before.
The white vertical lines are the zipper door that I will try to use in the summer time since this is just an over wintering greenhouse. It will open up a 4’ x 7’ opening when finished.

Millet
Does your mister system work on temperature or humidity?
Karl

http://img529.imageshack.us/img529/7702/dscn1842ef5.jpg

Karl, you will find that it is much easier to heat a greenhouse during winter, than it is to keep them cool during the summer. My misting system is neither temperature or humidity controlled (wished it was), it is controlled manually. - Millet

I just revisited this old post form February 2007 when I was considering a patio greenhouse. Odd how things progress, but with all of the advise given here, I progressed to an ever larger greenhouse. Today while picking tomatoes, jump-starting papaya for spring planting, I am impressed by all of the (beautiful flowers my wife not me!) things that grow so well in a greenhouse. I am in there every day and it’s awesome during a cold or rainy day to have this one special space where I have almost complete control of the weather. Thanks everyone and I finally get, that a greenhouse is something that you can’t really understand or appreciate until you have one.
Karl

Karl, I'm happy for you. I remember when you first posted this in '07...my, how time flies! Nice job.