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What is Polycarbonate?

What is Polycarbonate?

We’ve been living in the 21st Century for a little while now and while we may not have the flying cars and jetpacks science fiction predicted we might, modern technology is arguably pretty great. Sure your computer freezes up every now and again, but I’m willing to guess there’s not many who have access to up to date technology who isn’t better off for it. From modern medicine to advances in communications we have seen quite the technological revolution over the past 22 years. Yes, modern technology has seemingly had its hands in advancing most every facet of our lives. Even some of our more ancient traditions have been improved to be as modern as possible. That’s right, even todays farming practices are a product of modern advancements. Most greenhouses will (or should) have electricity running through them allowing the use of lights, heaters, fans, automatic watering systems, climate monitors and a plethora of other things that will assist you in your gardening efforts. One of the less obvious advancements you may be employing is the polycarbonate glazing that makes up your greenhouse walls or roof, shielding you and your plants from the elements outside. While you may know what it does, you may not know where it came from or even why it’s being used aside from it being cheaper than some glass options. Well, fret not more. In this blog, I will aim to inform you about the origin and the reasons for using polycarbonate!

So what exactly is polycarbonate? Technically speaking, polycarbonates are a group of thermoplastic polymers containing carbonate groups in their chemical structure. Not to get further into the chemistry weeds, but a carbonate group is essentially a salt of carbonic acid and that’s all I’m going to say on that subject… I was alright at chemistry, but explaining those topics was never a strong suit of mine. Basically, polycarbonate is a thermoplastic, which is a heat tempered plastic product that is significantly more durable than most other plastic products. The individual ‘compartments’ within each polycarbonate sheet contribute to the overall strength of the sheet. Along with the number of ‘compartments’ contributing to the strength, the thickness of the sheet can also increase the weather resistance. The thicker and more compartmentalized, the stronger the sheet. The stronger the sheet, the more wind, rain and sun resistance it is likely to have.  Hopefully that slight, if not confusing explanation gives you some insight into what exactly polycarbonate it.

Now that we have a rough idea of what polycarbonate is, you may be wondering, why are we using it? Polycarbonate is used in greenhouses for a multitude of reasons. Firstly, it can be less expensive than its glass counterpart. Glass is traditionally used for windows because of its ability to let sunlight pass through without the wind, rain or creatures living outdoors getting in. Greenhouses rely on their ability to let in and sequester the suns light as well as heat. This allows for the microclimate inside to be tailored towards growing plants. Polycarbonate is a cheaper alternative to sheets of glass while providing the same utility to your greenhouse. Some forms of polycarbonate, mostly the colored varieties, may have different levels of opaqueness than glass. But glass can just as easily be tinted to allow for less sunlight penetration, much like the windows in your car. Aside from being a cheaper alternative, polycarbonate sheets can be more durable than some glass. For example, if a wind storm starts to pick up twigs and rocks or other debris from the ground and send that crashing into your greenhouse, glass windows can shatter if hit with enough force. In some cases, polycarbonate will be more resistant to physical damage and is often more impact resistant. Really what I’m trying to get across is, it would be a lot harder to shatter a sheet of polycarbonate than it would a sheet of glass. This can not only make your greenhouse more durable, but also easier to clean up in the event of a crazy windstorm.

Of course, these circumstances are quite rare in occurrence so I wouldn’t go basing your glazing selection based on fear of windstorms and not wanting to clean up broken glass. It is still possible for your poly sheets to break, just not in as devastating a manner. As Charley will tell you, the main factor that people consider when picking between the two if price is not an option, is visibility. Glass is generally speaking, pretty clear. If you’re using high quality glass that isn’t made opaque on purpose, you should be able to see in and out of your greenhouse. That to mean, if you’re standing outside your greenhouse, you can see inside of it and vice versa. Polycarbonate, at least the varieties we offer, are by nature, opaque. This to mean that you are unable to see clearly through from one side to the other. You can still make out rough shapes and colors, but you probably won’t be able to identify what plants are growing within. Well, maybe you could if you have great eye sight and impeccable plant knowledge, but even then, you’ll probably give yourself a headache.

Other than durability and visibility, there aren’t many differences between glass and polycarbonate in terms of your greenhouse glazing. Glass might be a bit more sustainable in the long run as our polycarbonate sheets generally require replacements after 10 years of continued use (compare that to 2-3 years from less quality poly products). Glass is also more environmentally friendly simply for the reasoning that it’s not a plastic product. Though, the thermo-plastic material used to create polycarbonate sheets is hopefully (I have not actually researched this) durable enough to be recycled for use beyond greenhouse glazing. In both case, owning and operating a greenhouse can help you minimize whatever carbon footprint you have as you are actively growing plants and contributing to the exchange of oxygen and carbon sequestration that plants provide. Sorry, bit of a tangent.

So now that you know the basics of polycarbonate, you may be asking, is this all polycarbonate sheets are good for? Such a great product that can only be used for greenhouse windows? Fret no more! Polycarbonate sheets are a very versatile outdoor building material for many projects around your yard. If you live in the Pacific Northwest and you want to create an outdoor space with cover that will actually hold back the rain, look no further. Maybe you want to build a small storage shed but want to save some money on building materials. Polycarbonate is a great alternative that as I’ve mentioned earlier, is good to go for 10+ years depending on your needs. Trying to build a pool house? Many of us are (in our minds at the least). Polycarbonate sheets are a great material to help give your pool or spa house an outdoor feel while still providing the security and protection from the surrounding climate. As in your greenhouse, it can be sealed to keep moisture from penetrating so your hot tub will be safe from the rain as well as animals living in your area.

One of the more practical uses for polycarbonate sheets would have to be skylights. Skylights are small windows in your roof that can let extra sunlight into your living space as well heat resulting from said sunlight. Many people enjoy these in their homes to brighten up their spaces, provide light for indoor plants as well as just make the space look more open. Why polycarbonate just makes sense for this application is because of the differences between it and glass. With polycarbonate being stronger against impact than glass can make sure you don’t have broken glass on your floor and a hole in your roof if a tree branch lands on your house. Of course if the damage is significant enough, your building material won’t be the difference maker. The larger point behind polycarbonate being the superior skylight material is the fact that you generally don’t need to look out your skylight and you for sure don’t want anyone looking in them! Generally speaking the skylight is to let sunlight in, and what do we not do to the sun? Stare at it. While polycarbonate won’t block the sun from your vision, I’m willing to bet you’ll be a lot less likely to try and stare through it if it purposely blurs your line of sight. Of course you probably shouldn’t be staring out of your skylight in either case, a deterrent to remind you not to look at the sun is never a bad idea.

We here at Charley’s offer a variety of polycarbonate sheets ranging in both thickness to colorization. We don’t have an architect or landscape designer on staff so unfortunately we cannot assist in planning and drawing out your polycarbonate based designs, but we can very happily supply you! We offer essentially all you’d need for polycarbonate based projects including joiner caps which, as their name implies, joins two sheets of polycarbonate together. This ensures a weather tight joint between two sheets of polycarbonate allowing for extra coverage area without sacrificing structural integrity. We also carry a vent tape to cover the open ends of your polycarbonate sheets which will allow any moisture that gets in to evaporate without drying up and creating molds or other nasty things.

No matter what project you’re working on, if it involves polycarbonate sheets, we’ve got you covered. Just give us a call and someone can answer your questions and help you along your way! Thanks again for reading, join us again next week!


-Brian Bill

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Tim Banks - June 11, 2022

Hello, imm inquiring about the polycarbonate sheets.’2’ply sheets. Do you ship to Nyc. If so can the sheet’s be cut to size ,exampl 20 length/x 18 inches wide

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