It may not have been overlooked, it may just be hard to find someone who has used both.

From the adds, the obvious difference is that the solexx panels are opaque white, and supposed to provide more diffused light. I haven't used them so can't say for sure if it is real, or just marketing.

The clear double wall acrylic panels have been in use for quite some time, and are a known entity.

As far as insulating quality, well obviously thicker better.

Sorry I couldn't be more help.

Thanks Rush. I have a sample of the Solexx but have never seen the polycarb except in photos. They look the same to me.
What I wondered was if they were the same type of product. If so I could buy the HFGH kit and use the panels to build my own since I think it would cost less than the same number of Solexx panels. I don't like the HFGH frame for my circumstances.
Unfortunately I have no way of comparing the two products so i don't know which is thicker. I know the Solexx comes in 5mm which they recommend for colder areas. Aside from knowing the HFGH panels are twinwall I don't know their mm.

Thanks,
MollyD

The solexx (also sold as polycor)product is a high density polyethylene. The other panels , such as in the HFGH, are polycarbonate. One difference is the light transmission- about 85% for polycarb vs. 72% for the solexx. Looking at some of the guarantees that go with each type, the polycarb has a 10 yr guarantee (with actual in service experience of 20 years without problems). The sollexx , at least on one web site, comes with an 8 yr guarantee. As far as insulation value, the solexx actually claims a somewhat higher value than the polycarbonate. I looked at both and decided on polycarbonate because of the known life expectancy and better light transmission.

Thanks Cuestaroble,

That's exactly the type of information I was looking for. It sounds like the HFGH is a better deal for me. We get very little sun here in the winter (we just went through a 10 day stretch with an official total of 38 mins of sunshine)so I need the better light transmission. I can always add the solar pool cover for additional insulation.
Another question, the Solexx is screwed into the studs. Do you know if the polycarb can be installed this way?
8 yrs what Solexx warrantees officially.

MollyD

My panels, as were the ones we installed almost 20 years ago in a research greenhouse, were installed in metal or wood grooves. However, on some other threads, several people have mentioned using screws directly through the polycarb. The grooved channels work very well, allowing for expansion as needed. They also allow for a very close fit, reducing leakage.

Thanks Cuestaroble. Do you have any photos of this? I'm trying to get a mental picture and failing.

MollyD

Here is an option to attach the panels to the greenhouse frame. On the 2X3 support beam, a one-half inch piece of molding is nailed at the top edge. The panel is placed on this molding. On top, a similar arrangement to hold the panel down.

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Oh I like that! That's the way I want mine to look!! Thanks CR! Now I have a workable game plan on how to approach building this new GH. I'll buy the HFGH kit for the panels and make the same frame but out of wood with a really good anchor. I think that will give me the best of both worlds!

Thanks!
MollyD

One downside to that approach is that your wood is exposed to the elements, and the UV will kill the wood really fast. You might look for T shaped Al extrusions and use a similar design but with the T pushing the two panels down with wood on the inside.

Since the wood has already been cut from the cedar tree and no longer is rooted, it is actually quite dead now. A yearly application of clear, UV protectant to the exposed wood has kept the now 4-year old greenhouse in good shape.

Nathan,

I'm not in a high sun area. Even in summer it's not a major factor. Treated lumber can last some 20 years exposed and that's way past the life of the polycarb. I won't be growing anything that I'll eat so I'm not worried about using treated lumber.
As CR says a yearly coating of protectorant would take care of many woods especially here where I am.

Thanks!
MollyD

hehe, ok. I guess I'm speaking from experience in the high UV of the southern hemisphere.

I figured you were speaking from your own experiences in Australia. I understand the sun is quite strong there?

MollyD

The UV "experience" in Melbourne is probably not much different than that of central California. I was not able to get data on the two locations re: uv index, but perhaps someone could provide a web link to such information. It might be an interesting comparison

The UV index today was 11. for comparison, phoenix, AZ never got above 11 last year:
http://www.cpc.ncep.noaa.gov/products/stratosphere/uv_index/gif_files/phx_05.png

The UVB exposure in australia is probably 4 times that in central cal. Here's a map https://earthobservatory.nasa.gov/Library/UVB/uvb_radiation4.html
note that the hole in the ozone layer got significantly bigger in the last 5 years.

Tasmania is scary even for Melbournians. Hobart, 43S, is further south than New York City is north. In summer an hour of unprotected sun will give all but the darkest skins sunburn. I had one day walking around the alpine area of Tasmania with hat, and sunscreen, and I was blistering the next day. UV indexes of 15 are not uncommon.

Don't confuse UVB exposure with total power - central cal has a high total solar power, but the UVB is not significant. It is UVB that breaks down wood.

And I get so little sun here in the Fingerlakes that we just went through a ten day stretch with an official 38 minutes of sunshine for the whole 10 ten days! Can you see why I wouldn't worry about the sun?

MollyD

MollyD,

I read these posts and felt there were some points that needed clarification about the Solexx panels. (I helped develop the Solexx formula so I know the product and the industry well). Solexx panels have been around for almost 20 yearsand they are not the same as polycor. There are some products that look like Solexx, however, the chemical formulation is quite different. You cannot see the difference, but only Solexx is field proven and lab tested. WeÂve tested other materials (like polycor) sold as greenhouse materials and they lasted between 6 months and 1 year. The warranty on Solexx is 8 hrs, but it will last substantially longer.

Solexx will attach directly to your structure with a self tapping screw. Ideally you will have supports every two feet or so. Polycarbonate is generally installed in a channel and not attached directly to a frame. The polycarb will look very similar to the sample you have, however, itÂs much more rigid. From your sample you can see how the Solexx has some give when you squeeze it. The polycarb will not move at all. Polycarb comes in more thicknesses than Solexx, but any reputable reseller should tell you how many milimeters the walls are. Thicker is not always better because once air cells become large enough air can move in the cells which actually decreases the insulation. Solexx is unique in that you seal the cells on each side of the panel so there is less air movement than with another material of the same thickness.

If you are after the look of the clear panels rather than the white material, double walled polycarbonate will do a good job for you. Although the light transmission is slightly higher with polycarbonate than with Solexx, the light under Solexx is much more even and overall is brighter inside because the light hits every area of the structure. It does not have the intensity in one small area, but here are no shadows so itÂs actually brighter under Solexx. The diffused light may have even more of a dramatic impact in low light conditions. ItÂs difficult to explain in print, but itÂs obvious when you see the two side by side. Even on overcast days I often have to go into the Solexx greenhouse wearing sunglasses (I have really sensitive eyes). I donÂt have that problem in clear greenhouses because itÂs easy to turn away from the direction of the sun where itÂs not bright.

There is also a white version of polycarbonate which is much more expensive than the standard polycarbonate, which is often used by commercial growers. This white polycarbonate will diffuse the light much like Solexx. Acrylic is used in greenhouses as well, but IÂve only seen single walled material. Not only does it scratch very easily, it will provide no insulation and will trap a tremendous amount of heat.

Before you purchase a HF greenhouse for the panels there are few things you may want to consider. If you are only looking for the panels you may be able to find a source locally from a greenhouse or plastics supplier. You will likely get a much better quality material. There are a lot of polycarbonate makers now and the quality range is huge, and you canÂt always tell the quality just by looking at it. Some high quality polycarbonate brands carry a 20 year warranty, but some will last only a few years. IÂm not sure what the warranty on a HF greenhouse it, but I suspect you will be disappointed with the end result by going this direction not to mention you will pay more for a frame you donÂt want to use.

Good luck with your greenhouse! You will especially love having one in the winter when you donÂt see much of the sun.

mmoore

mmoore,
Thanks for your insight. You mention that polycor has a different chemistry than solexx. Without giving away trade secrets, could you explain what the main difference is? You mention that some commercial growers use a white version of polycarbonate. Could you say what crops they are growing and where, in general , they are located?
I realize this is probably not an issue for a 10X12 hobby grower, but perhaps we could learn something from the commercial growers.

Thank you Mmoore,

Would you know if any test were done for snowloads? Does this depend more on the framing than on the panels themselves?

I currently have a hoophouse which is working quite well so far but does not give me some features I need (such as a good way to vent, places to hang lights,etc).

I have not been able to find a distributor locally. I'll keep looking as I won't start building the new GH till it's safe to take down the old one. Most likely this will be April or May.

Thanks!
MollyD

Well I just found an online distributor for the Solexx who doesn't charge for shipping on small orders (10 or fewer panels)! That's a big plus in the Solexx column.

MollyD

cuestaroble,
There are quite a few makers of a material called corrugated plastic which is widely used for reusable packaging,
especially in agricultural applications. The most common resins used are polyethylene and polypropylene. They look almost exactly the same, but respond differently to impact and temperature extremes. The primary chemical difference between Solexx and other similar looking materials is the UV additives; however, there are several manufacturing concerns as well. Most plastics will break down rapidly in the sun, including polycarbonate, if not treated. Polycarbonate has a coating on one side that will protect the plastic from the UV damage. Solexx does not use a coating, but had the protective chemicals throughout the resin. Again, you cannot see the difference at all, but it becomes evident after exposure to direct sunlight. Recently we conducted a test with the Solexx material under lights that simulate the sun in Arizona. After the equivalent of 12 years of constant exposure, the Solexx showed NO signs of deterioration. Other corrugated plastic products we tested lasted between 6 and 18 months. This is also consistent to the field results weve seen.

Im not an expert on commercial growing, but I have seen quite a few greenhouses and do talk to quite a few growers. Im sure there is someone out there that can give you a more complete answer, but heres what I know based on my experience. Most commercial growers that use the shaded polycarbonate would do so with high value plants or if they are in an area where they have very intense sun exposure and have problems with overheating. Orchids would be an example of a plant that does not like the direct light but does well under bright diffused light. Strawberries are another crop that loves the high light and heat but will burn under a clear covering. The most common place for the shaded polycarbonate on the greenhouse is on the endwalls.

In some ways, the covering you use on your hobby greenhouse may be more important than that on a commercial structure. With a large structure its much easier to control the temperature. With a small greenhouse its easy to overheat the structure and overheating is one of the biggest causes of plant death in a greenhouse (this is for hobby greenhouses, so Im not positive it is also true for commercial growers). Also, the light intensity of clear materials will cause excess heat and a small greenhouse will get hot very quickly. Hope that helps.

MollyD,

Snowload is a bit tricky because it does depend a lot on the structure. We put 1200 pounds of wood pellets on top of an 8ft Solexx greenhouse and it held the weight. We added another 400 pounds and the roof sagged significantly, but it didnt fail. When we removed the weight the structure popped back into place. If the supports are strong enough to hold the load, the Solexx panels will hold the weight between the supports (provided they are placed about 24" apart), but it will not compensate for a weak frame. We have many customer testimonials and pictures of greenhouses that have been completely covered in snow, but its difficult to translate that to a custom structure because we dont know how they were built.

There is a chance that your frame would be strong enough to keep and cover with Solexx rather than starting with a new frame. You would need to figure out how to hang lights, but my guess is that you could build some simple framing and add vents and a fan. If you can save the frame and the labor you may have enough money left over to come up with some pretty creative solutions. Do you have a picture of your current structure?

mmoore

Thanks mmoore. Now, mollyd, would you care to share where you found the solexx panels with free shipping please.

Mmoore,

My current GH is just a hoophouse. I definitely want a new frame. I do the building myself so no labor cost are involved. I don't bring in any pros at all.

Cuestaroble here is that link you asked for:

This place is like a 1960's IQ test.

Solexx is to coverings as propane is to heating.

Given the above fact, then which of the following is false?

1, All cucumbers are green.

2, A greenhouse will cost at least twice as much as you estimated to build.

3, Solexx is better than polycarbonate.

4, Polycarbonate is better than Solexx.

5, An unvented heater is better than a vented heater.

6, A vented heater is better than an unvented heater.

7, No two hobby greenhouses will have the same requirements.

It all depends on what the goal is.

11 year bump. Anyone using Solexx out there?

Late to the party but I've had my Solexx for one year. I like it. Very easy to work with during construction, and a nice diffused light.

Morning from the great midwest. I purchased Solexx panels about 15 years age for my attached lean to type greenhouse. Easy to work with and a great product, cuts easy. Solexx has lasted and done a great job with the snow loads ( my pitch is about 65-70 degrees ). Like I said they have been installed now for about 15 years, they are starting to show age. Some areas on the outside face are getting thin and allowing an opening into the channels. Not a huge issue but it's about time to replace them. Kind of holding off that job because we might move and I'll build a different greenhouse. My greenhouse is 8'x12' with a ceiling height of 8'. i have always heated it with just a oil filled heater, a fan to circulate the heat and my minimum winter temp goes no lower than about 45 degrees. We are a zone 5 area. Mainly keep tropicals in it, May 15th they go into the ground outside and October 15th they get dug up and go into the greenhouse, For anyone who wants bigger plants please plant into the ground they grow much faster than in a pot. The top pic kind of shows the edge of the greenhouse.

Slightly better idea of the greenhouse.

Well, there is a lot of discussion about the Solexx, but I see very little about polycarbonate. I have sold both products for many years. I no longer sell the Solexx. It was my choice. I am not knocking the Solexx. I just find that the polycarbonate has more desirable qualities for my tastes. The Solexx is so soft that you can cut it with a utility knife. As far as I know the Solexx warranty does not cover hail damage. Almost all polycarbonate sheets have a 10 year warranty against hail damage. Polycarbonate should be cut with a table saw, circular saw or similar. Yes, the R value provided by Solexx is higher than 8mm twinwall polycarbonate as a general rule. But, there are other options available with polycarbonate. You can go with a thicker material 6mm, 8mm, 10mm or 16mm. You can also go with a 8mm or 10mm sheet with a triplewall design for a higher R value. There are many specialty sheets available in polycarbonate which address specific issues, ie heat build up. Polygal Polycoolite is specifically designed for this. It shows a light transmission of 50% which scares a lot of people away from it. But, this is an overall light transmission. Plants use light in the 450 to 700 nm range. If you look at the light transmission of Polycoolite in this range you will see that it actually between 60% and 70% light transmission. This is more than adequate for growth. Also, Polycoolite has diffused light properties. What this means is that the light is scattered evenly throughout the greenhouse. All parts of the plant will get equal light, even under the plant canopy. If you are looking for a sheet with higher light transmission Polygal Polymatte has 99% light diffusion with a 77% light transmission. Lexan also has a product with diffused light. It is Softlite with a 100% light diffusion with 85% light transmission. As I stated, lots of options with polycarbonate.

As far as back to the original question of buying a HF greenhouse just to use the polycarbonate, I would recommend against it. I believe they use a 4mm or 6mm polycoolite. I have had personal greenhouses with both of these thicknesses before. I have never had any problems with them. But, there are different qualities of polycarbonate. I would suggest just buying brand name sheets from a reputable vendor. The wind and snow load of both of these materials is pretty much dictated by the structure and how the sheets are fastened to the frame.

Here is a quick video on how to install polycarbonate sheets.
Installing polycarbonate sheets properly