I get this question a lot. What is the difference between a glass greenhouse and a polycarbonate greenhouse. I am going to assume that the frames are basically the same, so the biggest difference will be in the glazing material.
Glass greenhouses will be more expensive than a polycarbonate greenhouse. Especially with a curved eave. The glass is all tempered (safety) glass, even the curve. The curved tempered glass is more expensive than doing a curved polycarbonate. The twinwall polycarbonate is flexible enough that it is bent right onsite as you are installing the kit. There are no special tools or processes needed to do this. You just simply bend it over into the curved frame and attach it.
Looks are another obvious difference. The glass greenhouse will have more of a timeless look to it. I suppose if you want to use the word “fancier” that could even be applied. Just in looks, not in function. A lot of people don’t like the polycarbonate glazed greenhouse as it will be translucent rather than transparent. It will not be like looking through a window like the glass greenhouse will. Twinwall polycarbonate is made up of 2 sheets, an interior and an exterior. These sheets are both clear and would look much like looking through a window if you peeled the walls apart. Multiwall polycarbonate is much like looking down the end of a cardboard box. You will have the exterior and the interior sheet with a rib in between them. The rib will run straight between the 2 sheets, not curvy like in a cardboard box. This rib is what distorts your view. You can see color in a polycarbonate greenhouse, just not a clear form.
The glass greenhouse will not be as well insulated as the polycarbonate greenhouse. A single glass greenhouse will have an R value of approximately 0.95. A 6mm twinwall polycarbonate greenhouse will have an R value of around 1.6. This means that if you have the same size single glass greenhouse and polycarbonate greenhouse in the same location, trying to heat it to the same temperature, the glass greenhouse will cost you more to heat. It seems from the difference in the R value that it would be about twice as much. That is not the case. There is a formula that uses the size of the greenhouse, the difference in the temperature inside and outside the greenhouse, and the glazing material. If this is a consideration in your instance, the best way to determine how many BTU’s you will need is to actually do the calculations.
Breakage is another issue. Tempered glass will break if it is hit in the right manner. There is just no way around it. But, it is tougher than regular float glass, and it will shatter into small pieces, so safety is not a concern. Polycarbonate has a 10 year warranty against hail damage. It is a very tough material. It will not break like the glass.
Lifetime of the glazing material is the last issue I will discuss. Glass will pretty much last forever unless it is broken. Polycarbonate generally has a warranty that the light transmission will not vary more than a specified number in 10 years. This is just a fancy way of saying that it will not turn yellow or get brittle. Some of the manufacturers have extended their warranties to 15 and even 20 years. I have personally seen sheets that were 15 years old and still in use. They looked just fine. I have had reports back of 20 year lifetime on the material.
Glass greenhouses vs polycarbonate greenhouses? What is the conclusion. They both have their benefits, it just depends on which fits best into your needs. The best decision is to make sure to get a greenhouse, no matter what type. It will give you hours of enjoyment, produce food for your family, protect your orchids, and be the envy of your friends and neighbors.
With the long holiday weekend upon us, there is not a better time to visit a local display greenhouse. I have several favorites. I love to go to Bellingrath Gardens in Alabama. They have a beautiful conservatory. City gardens in New Orleans also has an excellent conservatory. Even the small town of Monroe, LA has the Biedenharn with a beautiful conservatory. If you have a little more time and can take a trip the Biltmore in NC will also take your breath away. Also, Calloway Gardens in GA has a conservatory with butterflies and plants. These are all probably within an 8 hour drive of our location. You will probably not have to go far to find several in your area as well. Take a young gardener along and inspire them. You will find many styles and sizes of conservatories and greenhouses to explore. This article is about a couple of photographers who have started on a quest to explore greenhouses in far away places. I am totally envious of them.
Magnus Edmondson and India Hobson’s greenhouse quest began in Oxford, England, at the Botanic Garden, on a Sunday morning. “We were the only people there, and it was so incredibly quiet,” they write. The only sounds were “gasps of wonderment” and the “occasional sigh.” From there, Edmondson and Hobson, photographers based in Sheffield, were hooked. They began what they call “a self-initiated Greenhouse Tour of the World”—they find, explore, and photograph greenhouses, potting sheds, polytunnels, conservatories, and other indoor spaces made by humans, for plants.
The same thing happens every year about this time. We are all still enjoying the warm weather of summer, getting the kids ready for school, and we forget about our beloved plants. I can’t tell you how many times in the past that Tom and I were installing greenhouses in the cold of the winter because they didn’t get ordered in time. Typically a greenhouse that is manufactured for you will take from 4 – 6 weeks for delivery. In the fall these lead times become extended, causing delays from the expected delivery times. This not only applies to greenhouses, it applies to polycarbonate sheets as well. They are typically delivered in 1 – 2 weeks, but in the fall they will take a week or sometimes longer past these times. So, even though it is really hard to think about it right now, if you are considering purchasing or building a greenhouse this fall, now is the time to start your decision process and get an order placed. Trust me, this I know from years of experience.
Yep, That is Tom and my greenhouse. We really do practice what we preach. We think everyone in America should own a greenhouse! This was a rare snow storm in SE Louisiana. I don’t think the neighbors could even believe that we were outside in this mess. Today I just wanted to take a minute to reflect on the beginning and growth of Advance Greenhouses. Fifteen years ago Tom and I were studying how to get on the internet. We knew the product we were interested in, as we had been selling and installing greenhouses for a while. Our first adventure with polycarbonate was in 1993. We got a book about 4 inches thick on how to set up a website and dove into it. What in the world language were those people using? Something I had never heard of before. I am sure we fought and cussed our way through it and came up with what was an absolutely horrible website. But, people started to find us. We also did a lot of local garden shows to put the word out. Fifteen years later, here we are. Through the years we have had the pleasure of speaking and working with many like minded people. We love flowers, but we also love fresh food that we have grown for ourselves. Our greenhouse has been multi faceted. We have stored my cherished hibiscus plants, started seeds for the garden, started annuals and perennials for the flower gardens and even grown some food hydroponically in our greenhouse. As I tell people, it is a learning curve to figure out exactly what will work in your greenhouse. There are some hard, fast rules, but we are all growing different plants under different circumstances. We all have to do a little bit of experimenting to figure out what works exactly for us. In closing, we are running some sales this month as a customer appreciation (also an appreciation for what we have thanks to all of you). Visit our website to see the specials. Our business is very personal and very rewarding for both of us. Thank You! Tammy and Tom